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Choosing A Portable PC For Music

PC Musician By Martin Walker

The attractions of making and recording music on a laptop computer are obvious, but choosing a laptop can involve you in performance compromises and compatibility problems. Here's what you need to consider if you're thinking of going mobile.

As I explained way back in SOS January 2001, buying a PC laptop to make music can be a hit-and-miss affair, with the possibility of audio interference, insurmountable clicks and pops, graphics problems, and otherwise lacklustre performance with MIDI and audio applications. However, that hasn't stopped plenty of musicians following their dream of being able to make music in the garden or on holiday, to record live gigs, and even perform live without having to drag around a van full of flightcases. For some the laptop is a second machine, sometimes used in isolation, and at others linked in some way to the main desktop PC to provide extra processing power. For others it has replaced the desktop machine altogether, and combined with a USB music keyboard provides a mobile (or at least portable) studio in a box.

Which OS For Laptops?

If your laptop features a Synaptics Touchpad it may be worth disabling its animated tray icon to achieve the lowest audio latency.If your laptop features a Synaptics Touchpad it may be worth disabling its animated tray icon to achieve the lowest audio latency.Many musicians still run Windows 98SE on their desktop PCs, where it can still be a stable and reliable OS if properly optimised. However, it's a different story with laptops, where Windows 98 has a history of causing glitches that can't be easily resolved except by raising the sound device's buffer size, and hence the latency. Thankfully this isn't an issue for many musicians, since any laptop bought in the last couple of years is likely to have Windows XP already installed. As in Windows 2000, XP's ACPI implementation is rather better than that of the 98 family, and a laptop that might manage a 23ms latency under Windows 98 can often cope down to an excellent 3ms under XP, although as always 6ms or above is likely to avoid extra CPU overhead.

It's still important to change the Processor Scheduling to favour background services, but one additional chore with laptops is to investigate the range of default Taskbar icons, most of which will be running something in the background. Most are unlikely to cause you any audio problems, although many laptops use a Synaptics Touchpad, and RME's excellent web site explains that disabling its animated tray icon will help you achieve a low glitch-free soundcard latency.

Centrino Of Attention

Today there are several basic choices to make, as I mentioned briefly in last month's Millennium laptop review. If you want a slimmer and lightweight unit (typically 2.5kg) with long battery life for a mobile music-making solution, one featuring Intel's latest Centrino spec including a Pentium-M processor might be the best solution. Red Submarine have recently added such a machine to their range, and Intel now offer a choice of Centrino processor speeds up to 1.7GHz. This might not sound very powerful to those used to desktop PCs, but the Pentium-M is designed with a high IPC (Instructions Per Cycle) rate so that it can do more work in fewer clock cycles, like the G3 and G4 processors used in Apple Macs. The inclusion of a huge 1MB Level 2 cache also helps provide rather better performance than you might expect — Intel claim that a 1.6GHz Pentium-M provides similar performance to a 2.4GHz Pentium 4-M (see next section). Moreover, Centrino laptops achieve their extended battery life as a result of lower power consumption, which means less heat is generated. In some cases this may mean no cooling fan to disturb the relative silence, although it's more likely that the fan will be as noisy as other laptop designs, but in action for much shorter periods of time (see Laptop Acoustic Noise box).

However, while the Centrino is ideal for the typical light user, offering up to five hours' battery time with office applications, it isn't likely to offer the same life with continuous high CPU activity, or where the hard drive is also in continuous use, which is after all exactly what a multitrack audio application requires. In this situation its Enhanced Speedstep technology (which drops processor speed almost instantaneously from 1.6GHz down to 600MHz in five stages depending on processor load) won't be so appropriate, and may have to be disabled to achieve maximum performance, which will also cause battery life to drop.

Deeper Sleep mode is an enhancement of the Pentium 4's Deep Sleep, dynamically switching the processor to a lower operating voltage within a few hundred microseconds whenever possible — again, this will help in many applications, but is just not relevant for the sustained real-time performance of music software during recording and playback. It might extend battery life in some cases when idling, although much music software still consumes plug-in and soft synth overhead in this state.

Because of these factors, there are conflicting reports on the suitability of Centrino models for music applications, with some people maintaining that they could prove more powerful than standard Pentium 4 laptops, and others maintaining that their strengths are light weight and long battery life at the expense of raw power. I'm hoping to get hold of one shortly for review, but until then I'm still confident that it would be entirely suitable for anyone wanting to run a few dozen audio tracks plus some plug-ins and the odd soft synth.

Dial M For Mobility

Another mobile solution is Intel's Mobile Pentium 4-M processor, which is available with much higher clock speeds than the Pentium-M — in June 2003 Intel introduced a 3.06GHz model. The Pentium 4-M chip starts life as a standard Pentium 4 wafer, but is run at a lower supply voltage than the standard P4 range to significantly reduce power consumption, and is then further optimised with a range of special lower energy consumption technologies to extend battery life compared with its desktop counterpart. As its origin suggests, the Pentium 4-M can provide the same sustained performance as a laptop featuring a standard Pentium 4 processor — but only if you once again abandon these energy-efficiency features such as the lower fixed 1.2GHz clock speed and lower core voltage of its Battery Optimised power scheme, which rather defeats the object. It is also likely to require some sort of forced cooling when its CPU is constantly active, which nearly always means a cooling fan.

However, it does seem to be a promising solution for a musician who wants the best of both worlds: longer battery life when required at the expense of sustained performance, but plenty of processor power when optimised for audio applications. Most recent laptops based on the Mobile Pentium 4-M are touted as 'desktop replacements' or 'desknote' machines, and typically weigh in at 3.5kg or more, which makes them 'portable' rather than 'mobile'. The only negative point I've encountered about Pentium 4-M designs is the occasional report of a laptop that won't revert properly to full speed, even when all its energy-saving features switched off.

Laptop Acoustic Noise

In general, standard desktop PCs tend to be far noisier than laptops, although once you've fitted a quiet PSU, hard drive enclosure and quiet CPU fan to one, there may not be a lot in it. However, when auditioning suitable laptops, remember that you don't have the option of sticking the laptop out of the way under the desk or in a cupboard.

If you want to hear how noisy a particular laptop can get, the Idlemess utility from German magazine c't can be used to occupy your processor permanently at up to 100 percent overhead, which should soon force any cooling fans to be activated.If you want to hear how noisy a particular laptop can get, the Idlemess utility from German magazine c't can be used to occupy your processor permanently at up to 100 percent overhead, which should soon force any cooling fans to be activated.Many older PC laptops use continuously operating cooling fans of around an inch in diameter, which produce a higher-pitched whine compared to the 60mm units used in most desktop models, and can thus be more annoying. Thankfully, though, most modern PC laptops (even the majority of Centrino models) now have a thermostatically controlled cooling fan that only operates once the CPU reaches a certain predetermined temperature, and then switches itself off as soon as the temperature drops again. This, plus the complex arrangements of heat-pipe technology that are often used, means that while a particular laptop may be extremely quiet when first switched on, you won't find out how annoying its fan is until later on, since fan noise can vary considerably from model to model. Moreover, fan noise is very subjective — what one person may find perfectly acceptable may prove incredibly annoying to another.

If you're about to buy a PC laptop, try the model in a shop until the fan operates if you don't want to get a nasty surprise — after all, unlike a desktop machine, changing it for a quieter unit isn't usually feasible. A quick way to do this is to download the NoIdle.exe utility from German magazine c't (ftp://ftp.heise.de/pub/ct/listings/0107-236.zip) — this is a 32k stand-alone file that can be quickly transferred from a floppy disk, and can continuously run the CPU flat out at 100 percent, which should soon start up any cooling fan. Be wary of claims that you can permanently disable the fan in some models, since this may only apply when using one of the power-saving technologies that drop the clock speed significantly.

Whether or not your PC laptop has a cooling fan, there are various ways to help keep it running cool. First, don't place it on a soft surface like a cushion or bed, as this will often cover cooling vents or fan intakes and cause overheating and even emergency shutdown. To aid cooling airflow you could stand your laptop on rubber feet, or use a custom-designed solution like the Road Tools Coolerpad (www.roadtools.com), which raises up any laptop slightly to promote the free flow of air, as well as providing a handy 360-degree swivel function.

Other more technically advanced approaches place your laptop on a pad of phase-change material (www.climator.com), which absorbs heat and then dissipates it once your laptop has been switched off, or on a Nexus Thermal Innovation pad incorporating heat pipes that draw the heat away from the bottom of your laptop. Both mats cost between £25 and £30, and the theory is that by removing the heat, the onset of fan noise can be considerably delayed and in some cases eliminated altogether, while extending battery life slightly. They can be extremely successful with some laptops where contact area is good, but if your laptop doesn't have a flat bottom, or has fan intakes or exhausts there, they make little or no difference, as I found after some experiments with the Climator phase change mat and the Millennium laptop.

The Fourth Dimension

Both the Centrino and Mobile Pentium 4-M currently use a 400MHz buss, and are ideal in their different ways for extending battery life. For maximum performance, however, there's a third approach: using a standard desktop processor such as Intel's Pentium 4. Like the Pentium 4-M, it's available in laptops at speeds of up to 3.06GHz and supports hyperthreading, but it can also run with a front side buss speed of 533MHz, and, best of all, is significantly cheaper than any Mobile processor option. The down side is a rather shorter battery life, although this is often offset by manufacturers specifying a more powerful and heavier battery capable of supplying 60 or more Watt hours instead of the more usual 40 Watt hour devices included in slimline and lightweight Centrino models. Using a standard P4 also means significantly greater heat generation, despite the lower power requirements of the smaller Northwood 0.13 micron core compared with earlier P4 processors, and the consequence is that the cooling fan will probably be on more often.

A standard Pentium 4 laptop is probably the most suitable option for those musicians who want the ultimate performance in an all-in-one compact unit, and who will normally have it plugged into the mains supply anyway. Before anyone prematurely discards this option as missing the whole point of buying a laptop, let me reassure you that many professional musicians I spoke to have already come to this conclusion, and specialist music laptops available from Digital Village, Millennium, Philip Rees and Red Submarine all adhere to this philosophy.

The primary attraction is a powerful PC in a compact package that can easily be moved from place to place. Another is that a 2.4GHz P4 laptop can currently cost between £300 and £500 less than a roughly equivalent 1.6GHz Centrino model or 2.4GHz notebook featuring a Mobile P4-M processor, although this may change as Intel continue to market their Mobile Pentium 4 processors more aggressively.

Those who simply want a smaller PC could consider Red Submarine's Mini-Sub (reviewed in SOS August 2003), or machines based on the Shuttle chassis from (among others) Philip Rees and Red Submarine, but these will still require a separate monitor, keyboard, and mouse, making them far less convenient when moving from place to place.

By the way, before I'm accusing of having an Intel bias, AMD's Mobile Athlon XP range seems to feature far less often in PC laptops than Intel's various processors, and when it does, is mainly available on much cheaper sub-£1000 entry-level models. Like the standard Pentium 4 models, AMD's Athlon XP range can also be found in 'desktop replacement' machines, although they don't seem to be as popular either. Moreover, while AMD motherboard chipset incompatibilities with audio peripherals are far less common nowadays, if you do hit a problem with an AMD-based laptop you're in serious trouble, as you can't change the motherboard.

The Small Print

Most laptops now have the advantage of 14-inch or larger displays, but do make sure that you're getting dedicated video RAM rather than shared graphics, since this will significantly boost performance. Laptops nearly always provide a comprehensive array of I/O options, but remember that while a few internal components such as the hard drive and RAM may be upgradable, they are nearly always more expensive than desktop equivalents, and you're stuck with the other components, so don't skimp on your main purchase.

Whichever laptop type and model you choose, get the fastest processor you can afford, and plenty of RAM (512MB is a good starting point if you want to run lots of soft synths), and preferably a faster-than-average laptop drive if you want to achieve plenty of simultaneous tracks — while desktop drives used by musicians are mostly 7200rpm, many laptops have 4200rpm or 4800rpm drives, although 5400rpm ones are available. Finally, before getting out your credit card, do try out the model you want to buy if at all possible, and check on any returns policy. UK Trading Standards recommend a seven-day 'cooling-off period', but some companies provide up to 30 days to get a full refund if you change your mind on such an expensive item.

Extending Battery Life

As explained in the main text, it's not only the spec of the laptop that determines battery life, but the type of application you're running. With a Mobile Pentium 4-M, typical office applications can run for three or four hours, whereas continuous DVD playback may drop this to two to three hours, and audio applications can ramp up CPU consumption and hard drive activity to limit battery life to between one and two hours. As a rough guide, a Centrino system might extend life by an extra hour compared with a Mobile Pentium 4-M system, bearing in mind that most slimline lightweight systems have lower-capacity batteries, while a standard Pentium 4 system might offer only an hour and a half with light duties, and an hour when run at full whack.

If you are attempting to make location recordings where mains power isn't an option, it makes sense to ensure that your battery lasts as long as possible. Laptops with interchangeable bays like the Millennium model I reviewed last month normally have the option of a second battery, which can almost double the operating life, although most Li-On laptop batteries seem very expensive. For marathon sessions, you can also buy laptop DC/DC converters that run from car batteries, or a 12 Volt DC to 240 Volt AC converter to use in conjunction with your existing laptop mains adaptor, which may be a considerably cheaper option.

Thankfully, the Li-On batteries found in most modern PC laptops don't suffer from the NiCd and NiMH 'memory' problems, so don't require full discharging before you recharge them — you just plug in the mains supply whenever available to top them up. Some laptop manufacturers still routinely recommend you completely discharge and recharge the battery once every month to maintain it, but this is outmoded advice and may reduce Li-On life expectancy — a regular mains top-up is better.

There are also various steps you can take to minimise power drain. One of the most obvious is to unplug any power-consuming peripheral when you're not using it. This includes many USB devices, which can take up to 500mA per port, although a USB optical mouse will only take 100mA, and a standard one a tiny 20mA or so. PCMCIA cards often take considerably more power (up to 1 Amp is available on the Cardbus), so if battery life is important to you it also makes sense to buy a sound peripheral that does exactly what you need — a simpler stereo device will take significantly less current than one with mic preamps, multiple ins and outs, and so on.

One way to increase battery life on a laptop using a standard desktop processor is to use a utility like Cpuidle, although this may not work with all versions of Windows.One way to increase battery life on a laptop using a standard desktop processor is to use a utility like Cpuidle, although this may not work with all versions of Windows.Turning down screen brightness may provide a helping hand, and if you have a dual-boot setup, you may also find it helpful to see if any other system devices have options to 'Allow the computer to turn off this device to save power' — just look in the Power Management page for each device inside Device Manager, and for each USB Hub entry. Also, if your laptop has interchangeable drive bays, only plug in the devices you actually need at the time, since a second hard drive can typically consume 0.8A.

Those using Pentium-M and Pentium 4-M processors can take advantage of the full range of special technologies at their disposal, although they may have a significant effect on the overall performance of MIDI + Audio applications. Remember that some of the selection of Power Management schemes, such as those named 'Presentation' or 'Max Battery Life', will seriously affect processor speed in favour of longer battery life.

Anyone with a standard Pentium 4 or other non-Mobile processor can try using one of the many utilities that reduce CPU power consumption by sending it a HLT instruction whenever idle — this forces the CPU into suspend mode until an interrupt occurs, which will also reduce temperature and therefore possibly fan noise. Cpuidle (www.cpuidle.de) is one of the best, with many users claiming significant drops in CPU temperature under Windows 98/Me, but apparently Windows NT, 2000 and XP already call HLT by default when idling, as long as ACPI is enabled. I downloaded Cpuidle Pro version 6.0 for Windows NT/XP, and after timing tests with and without its various CPU/chipset optimisations enabled as well as the HLT option, I didn't measure any difference in battery life on the Millennium P4 laptop running XP.

Motherboard Soundchips

As I explained in some detail in my previous laptop feature, all bets are off when it comes to built-in laptop audio quality. Although some companies now seem to be making more of an effort, perhaps because their customers are using laptops to play back audio CDs and DVDs, components will be packed more densely than in a desktop machine, internal shielding may be insufficient to prevent noises passing from one device to another and getting into the audio signal path, and you may get further digital noises due to the switching-mode power supply, plus others that accompany mouse, drive or graphic activity. Consequently, motherboard audio is still not a serious solution for the vast majority of musicians, and there can still be problems even when you use high-quality external audio peripherals.

If your laptop soundchip is supported by the generic ASIO drivers provided by Asio2ks you may be able to achieve low latency while running Cubase SX or other ASIO applications.If your laptop soundchip is supported by the generic ASIO drivers provided by Asio2ks you may be able to achieve low latency while running Cubase SX or other ASIO applications.However, a native sound chip can still be useful for monitoring, particularly when using headphones away from the studio, and nearly all laptops provide some sort of audio support, ranging from basic 16-bit stereo through to 7.1 surround sound playback with S/PDIF digital outputs. Sadly, though, some musicians who fancy dabbling with soft synths on the move will find latency a real problem with motherboard chipsets — modern WDM drivers may provide usable results for Sonar owners, but Cubase owners won't have the luxury of ASIO drivers. There is light on the horizon for some motherboards with the Asio2ks generic ASIO driver I mentioned in PC Notes June 2003 (www.asio2ks.de). This already works with some motherboard sound chips under Windows 2000 and XP to provide latencies below 10ms, and would prove a huge boon to Cubase laptop users who don't want to buy a specialist sound device.

Using laptop motherboard audio for recording purposes is less likely to be successful, especially since many laptops don't offer line-level inputs.

Solo & Shared Audio Devices

If you do want to take advantage of the higher sound quality provided by a dedicated audio device, PCMCIA laptop audio interfaces can offer one huge advantage: portability. This explains, for example, the current popularity of Echo's Indigo, which provides high-quality 24-bit/96kHz audio in an unobtrusive package that would suit anyone on the move. However, the Cardbus can only deliver 3.3 Volts at a maximum of 1 Amp, so multitrack audio devices (especially those incorporating mic preamps) are likely to need an additional power supply. RME's Cardbus/Multiface combo is one such device that's ideal for any laptop owner who wants plenty of inputs and outputs, and although it is supplied with an external power supply, it can also be used with a low-cost 12 Volt battery when mains sockets are unavailable.

Those who use both a desktop and a laptop PC may be more interested in using a single audio interface that can be shared between the two. There are already plenty of reliable USB sound devices available that will provide excellent audio quality up to 24-bit/96kHz stereo. Some, like Edirol's UA20 (SOS February 2003) and Digidesign's M Box (SOS June 2002) are USB-powered, which will be of interest to those who want the most mobile laptop setup. However, in general the USB 1.1 spec doesn't provide enough bandwidth to allow simultaneous recording and playback in the 24/96 format, so if you need more simultaneous channels Firewire is more appropriate until USB 2.0 peripherals become more available.

If you already have a desktop soundcard with a digital input, why not equip your laptop with digital I/O in the same format, and then let them share a high-quality stand-alone A-D or D-A converter box? Models are available at various prices, with one of the ultimates probably being Apogee's Mini-Me (reviewed in SOS June 2003). This approach will also allow Cubase users to employ Steinberg's VST System Link technology, locking the two PCs together via their digital audio connectors.

Serial, parallel and USB MIDI interfaces can also be shared between desktop and laptop PCs, although once again it may be useful to have a separate one for each so that you can use the laptop as a stand-alone soft synth to run alongside your main machine (System Link users don't need MIDI on the second PC).

Shared Storage

An external Firewire drive is an ideal companion to PC desktop and laptop computers, since you can move an audio project from one to the other without rebooting.An external Firewire drive is an ideal companion to PC desktop and laptop computers, since you can move an audio project from one to the other without rebooting.Sharing storage devices between a laptop and desktop PC provides the ability to move ongoing audio projects from one to the other without going through the rigmarole of burning CD-ROMs or setting up a network. For transferring smaller files under 1.44MB a floppy drive is still useful, although some PCs (like many modern Macs) are already dispensing with these. Using external SCSI hard drives has always been a great way to move larger amounts of data between machines, but you have to power down and reboot before reconnecting them to a different PC. Now, with both USB and Firewire standards, you can hot-plug a high-capacity storage device, making it easy to access projects within seconds from different machines.

Moreover, buying an external Firewire hard drive to provide more storage and possibly better performance for laptop audio recording is often easier and sometimes cheaper than upgrading its internal hard drive (if that's even possible). This is also a useful technique if you use one fast PC for most of your creative work, but want to press a slower one into service for burning audio CDs or creating backup files while you carry on working on the main machine — it's quicker than using drive caddies, and may well end up cheaper too.

Another handy way to transfer smaller amounts of data between desktop and laptop PCs (and Macs for that matter) is those tiny key-ring sized personal storage devices that plug into any USB port and appear to Windows 98, ME, 2000 or XP as miniature hard drives. They use flash RAM attached to an Advanced RISC Machines chip, and are available in sizes from 16MB from about £30 up to about 512MB at several hundred pounds. Using them is far quicker than burning a CD or writing to a floppy when smaller file sizes are involved: transfer rates are around 12Mbits/second. Even the 16MB model would be ideal for transferring update files for music applications from one Internet-enabled PC to another set up purely for music purposes, while larger models would be suitable for transferring your song data to your laptop when you're on the move, or even to another studio for mixing or mastering. Suitable models are available from Disgo, Iomega and Sony among others.

Promises, Compromises

As PC laptop technology progresses, I expect that a 'mobile' processor with fanless cooling will become powerful enough to run a software studio with fewer compromises. However, I suspect that with today's technology, any musician with dreams of buying a slimline and lightweight PC laptop that provides four to five hours' battery life when running numerous soft synths, plug-ins, and audio tracks may be seriously disappointed. This lifespan is quite possible when running office applications on a Centrino machine, but stressing the CPU as music applications do can ramp up its power consumption by a factor of four. Even where mains power is available, moreover, the jury still seems to be out on the Centrino laptop's performance with music software until more tests have been completed — I hope to provide an update within a month or two once I can get my hands on a suitable review machine.

At the other extreme, the standard Pentium 4 desktop replacement option favoured by many musicians (as well by nearly all specialist music retailers) offers guaranteed high performance for a lower cost — but at the expense of a thicker, heavier package, much shorter battery life and the possibility of a cooling fan being more troublesome. Occupying the middle ground, a Mobile Pentium 4-M solution provides guaranteed power performance, plus the option of longer battery life than a standard P4, but at a somewhat higher price.

Published October 2003