Machine Heads

Whether you're buying or building, deciding what should go inside an audio PC isn't easy, so we asked some leading experts for their advice...

If you're in the market for a new PC, you can't fail to have noticed the bewildering array of options for processors, motherboards, graphics cards, hard drives, power supplies, and so on. There's also so much misinformation about the audio pros and cons of USB 2 and 3, Firewire, and so on, that many potential audio PC purchasers and self‑builders grind to a halt in confusion. It can be a minefield — so we've asked some of the most experienced specialist audio PC builders a range of questions designed to help you make your buying and building decisions with more confidence.

Cores & Clocks

The first choice to be made in specifying an audio PC is the processor (Central Processing Unit, or CPU), because this will determine the most suitable motherboard chip set, narrowing down your motherboard short‑list, and in turn defining the type and speed of RAM you can use. Intel seem to rule supreme in audio circles, so the main choices boil down to clock speed and the number of cores. New processor ranges seem to pop up every few months, so I asked the panel of experts to comment on their feelings about the processors now available, and how to decide whether two, four, six or more cores are most appropriate.

Pete Gardner, Scan 3XS (Pete): "Hardware requirements are dictated by intended use. For instance, a recording rack for live audio would only require a low‑power solution, whereas the system back at the studio — where all the editing takes place — will certainly require something with more processing power to keep the session moving smoothly. Then there are some artists working completely inside the box who really push the envelope where processing power is concerned. The only constant seems to be that as the software becomes more complex, it will eventually find a way to consume whatever overhead you make available.”A professionally built audio PC such as this may look impressive, but how do you or the manufacturer decide which components to use?

Robin Vincent, Rain Recording (Robin): "The more cores you have, the more stuff you can do; it's very scalable and measurable. It has a direct impact on the number of plug‑ins you can run and the polyphony you can attain, so aim as high as you can with the CPU to give as much future headroom as possible. The new Sandy Bridge processors are very exciting, attractively priced and are turning out to be great performers. The high‑end Intel X58 processors look a bit lazy in comparison.”

Scott Chichelli, ADK Media Group (Scott): ”The majority of the time, GHz reigns over core count within the same product line. For example, a single six‑core 3.33GHz model [such as Intel's Core i7 980X] will outperform dual Xeons up to six‑core 2.8GHz. On a laptop, a dual‑core 640m 2.8GHz outperforms the slower-speed quad cores. However you have to be cautious, as a 600‑series dual‑core 3.6GHz [Core i5‑680] is slower than a 2.66GHz Quad‑core i5‑750. In some cases, more cores are better, such as very large 96kHz projects with heavy effects or large orchestral libraries. At that point, you need high GHz and dual Xeons.”

Simon Field, Direct Resolution (Simon): "Intel's QPI [QuickPath Interconnect, first introduced in 2008 on Intel's Core i7‑9xx processors] and integrated memory controllers mean that the bottlenecks of previous‑generation Intels have been lifted. While there are some overheads, both for hyper‑threading and scaling, systems now have options for 8, 12, 16 or even 24 threads. Recording software is well placed to take advantage, with plug‑ins getting distributed across cores much more evenly than with office or game applications.

"Sandy Bridge processors are showing signs of great performance, with their new dynamic Turbo Boost feature receiving a cautious thumbs-up during testing. The motherboard choice is proving vital. We have to be aware that musicians are a small market for Intel, and while power‑saving features, low energy models and integrated graphics are all areas they are looking to develop, they become more things to disable for the audio computer.”

Your Requirements

Once you've decided on a CPU, there are other things to consider before deciding on a motherboard make and model. I asked the experts how much their system specs vary depending on whether the musician needs low latency (for monitoring with plug‑in effects or live performance of virtual instruments) or simply sheer power, for heavy‑duty sampling or mixing.

Simon: "For most people, funds are finite, so it's important to identify whether you need the fastest RAM and lots of hard disks for low‑latency sample streaming, or more cores and threads for mostly mixing work. An engineer who tracks and mixes bands could be happy with 4GB of RAM and a quad‑core CPU — although we have composers who use 24 threads, 48GB [of RAM] and five-plus hard disks.”

Scott: "For live tracking of between eight and 192 input/output tracks, but without the requirement of lots of CPU power, I'd recommend a P67 [Sandy Bridge 32nm family] chip set for most musicians, adding RAID [multiple hard‑disk arrays] for higher track-counts, but an X58 chip set if a five‑drive RAID 5 [which requires a minimum of three hard drives, for two drive's worth of storage plus redundancy information] is needed to cope with really high maximum track counts. A composer needs the fastest CPU with P67/X58, but for running the full Vienna orchestral library a high GHz Dual‑Xeon may be required — or several slave PCs.

"For live sample playback, once again go for the highest GHz you can afford with a P67/X58. The same applies for a system intended for low‑latency mixing/punch‑in/layering, although for absurdly large 96kHz projects a high GHz Dual Xeon may be required. Finally, for light home‑studio use, processors are so fast today that most CPUs are fine with a H55/H67/P67 [chipset] system.”

Pete: "We're lucky we find ourselves at a point now where a good mid‑range machine really can do it all for a lot of users, but different requirements can mean that you have to consider more specific solutions. The specifications we develop are good all‑rounders, but if a user has certain requirements to meet, we'll always aim to develop the best working solution.”

Robin: "We aim to create a [system] that will do everything you need, regardless of your application, to build in an assurance of compatibility, stability and power. Our Element Pro Studio, for example, is built for low‑latency performance, it's perfect for heavy sampling, excellent at streaming tracks and contains the appropriate technology to achieve that. All of our systems work in this way, so someone with a £600 (circa $950) budget is just as assured of getting a great solution as the person with a £2000 ($3200) budget, the only difference being the amount of power at their disposal. Few people do only one thing these days, and our systems reflect this.”

Memory Choices

Now that triple‑channel RAM is becoming the norm for most processor ranges, and 6GB (three 2GB sticks) seems a useful default configuration to accompany an operating system like Windows 7 64‑bit, I asked the panel whether many of their customers would truly benefit from even greater amounts of RAM, and just how critical they feel the associated bus and RAM speeds are to the overall performance of an audio PC.

USB 3 is included on many motherboards now, but there's a lack of take-up by manufacturers of peripherals such as audio interfaces.Scott: "The more sample libraries you are using, the more RAM you need — it's that simple. Most small studios still don't need more than 4‑6GB if they do a little sampling, although for long‑play live tracking 8GB is more appropriate.

"Dual versus tri‑channel, 1066MHz versus 1600MHz RAM? For sample streaming, more is better, since if you run out of RAM you have to bounce. Given a choice, I'd take 12GB of 1066 over 6GB of 1600. For a composer, tri‑channel 1600MHz RAM will yield slightly better results than, say, 1333 or 1066MHz. Tri‑channel RAM has more bandwidth than dual‑channel, which equals more sampling at a lower latency. However, with the Sandy Bridge processors, things have changed some.”

Simon: "Even with a mix of 32‑bit and 64‑bit plug‑ins, using bit‑bridge software means one can use the full amount of installed RAM. You shouldn't just install the maximum you can afford, though: whilst too little memory will affect performance and workflow, having more than you use will not benefit you at all [and so could be unnecessarily expensive]. With customer enquiries, we go through the plug‑ins already being used and ones that might be invested in, and then work out the ideal amount to install. We normally also try and leave half the slots free to aid upgrade paths.

"Now the memory controller is on the same die as the CPU [in the Core i7 series], RAM speed does make a bigger difference. For a heavy sample user, the faster 1600MHz+ RAM with tighter timings, paired with the increased bandwidth of triple‑channel mode, means being able to work at lower latencies, and thus more responsive virtual instruments. However, a track- and mix-based setup is less affected, and standard (by no means slow!) 1333MHz makes more sense.”

Robin: "The advantages of memory speeds are difficult to define and measure. It's more important to correctly match the memory to the needs of the motherboard, to ensure stability. As virtual instruments get more complex and sample libraries more intricate, RAM is an increasingly significant factor in realising their full potential. It's also the easiest thing to upgrade, so you can opt for modest amounts now and add more as you need it.”

Pete: "We find that most users, depending upon their platform, go for between four and 12 GB of RAM, so in that respect 64‑bit platforms have proved to be essential. We've built machines dedicated to orchestral scoring that have 24GB installed, only to then add yet more RAM as the user's needs have become more complex. While this certainly isn't a common configuration, the indication is that continued increases in sound quality and other features will continue to push the requirements upwards.”

Connectivity

Once the customer's basic spec is established, we come to the I/O options — but there are so many! Apart from all the modern 'must-haves', such as PCIe slots and USB 2 ports, legacy PCI slots may still be vital for some people, or the sometimes problematic Firewire ports, Ethernet and wireless options may also be important, while USB 3 requirements can be anything between a novelty and an external backup necessity. I asked the experts what I/O they think is most important now, and what's likely to become important in the future for the musician.

Pete: "The I/O world is currently in a state of flux, with new standards failing to be adopted and old ones remaining desirable. Previous moves to speed up the adoption of the PCIe standard have reached the point where the PCI controller has been moved off the chip set [with Sandy Bridge], leading manufacturers to handle it through non‑native solutions. Rather than seeing this lead to the expected decline, we see newer boards appearing with more PCI slots than many of the last generation!

"Meanwhile, audio manufacturers have been slow to develop PCIe interfaces, and a year after the arrival of USB 3 we are also still without audio devices designed for this standard — even through it offers more bandwidth than the older Firewire ports (which continue to disappear from newer motherboards). Making USB 3 native in forthcoming chip sets will accelerate its growth, without a doubt, but we could still be a few years away from seeing it accepted enough that it becomes the default connection, leaving us with motherboard manufacturers currently trying to include all the various connections to keep everyone happy.”

Scott: "Any good new motherboard will have SATA 600, USB 3, Texas Instruments Firewire, and so on. PCI is on the way out soon. I hate to speculate on future connectivity — as you see, so far no one has adopted USB 3, and while Light Peak [the development code‑name for Intel's new 10Gbps 'Thunderbolt' optical I/O protocol] looks good, where is it? The I/O choices are really more about a client's workflow and budget. Not everyone can afford a nice PCIe interface and A‑D/D‑A converter to go with it, nor do many need it. The fact is that Firewire and PCI are still very viable connections.”

Simon: "PCI remains very popular with those who are upgrading a current DAW system. USB 3 is present on most motherboards, good for external drives (although they don't currently take advantage of the speed available), and may prove useful for audio interfaces. Ethernet and wireless are often used, but it's important that their effect on low‑latency audio is known (we provide advice on how to work with these so that they don't interfere with your DAW).

"Firewire is still the connection used most for mid-range to high‑end audio interfaces. We only use the Texas Instrument chip set, which results in few problems, but for laptops and off the shelf PCs it can be a minefield. For the future? Light Peak could become the one to watch.”

Robin: "Each form of connection brings its own challenges. Firewire is still greatly favoured by the industry, with the majority of 'pro' interfaces based upon it, provided it's combined with the right Firewire card. The next generation of connection, like Intel's Thunderbolt, needs to appear on every device and give consistent performance — the key is the scale of adoption as much as data-transfer performance.”

Drives & Storage

Modern 7200rpm hard drives are extremely capable for audio purposes — yet the forums are awash with musicians asking about 10,000rpm models, RAID, and solid‑state drives (SSDs).Pete Gardner I wanted to find out just what proportion and type of customers our panel of experts think would actually benefit from such luxuries, and why.

Robin: "10,000rpm drives are noisy, hot and come in low capacities for loads of money. RAID can add complexity and make things more difficult to fix when something goes wrong. Solid-state drives are slightly different, because they don't really have a down side; no noise, no moving parts, low power, small footprint, fabulous performance — it's only the price that stings a little. With a good SSD, Windows boots up quicker and is much nippier to use, and in audio terms, sample libraries stored on SSD load much faster. There are some real time‑saving advantages and they are less prone to failure.”

Scott: "A standard 7200rpm drive is capable of well over 100 tracks running at 48kHz, or over 50 at 96kHz. Why complicate it? 10,000rpm drives and SSDs are a luxury, not a requirement, and often a foolish investment. Throughput on 10,000rpm drives is no better than standard SATA any more, the only benefit being lower seek times, which would help a little with sample pre‑load. Samples are far less disk‑streaming than before, and with larger drive caches on standard SATA drives pre‑loading is increased.

"Choosing SSDs would make more sense if they were more affordable and larger. Right now, the only thing I recommend them for is a laptop for live gigs. Yes, they make great sample drives with near-instant loads, but anyone with any serious libraries will need multiples, at a great cost. It's just as easy (and nearly as good) to spread your libraries over multiple SATA drives with a large cache (64MB). If you have the cash for an SSD, spend it on a faster processor!”

Simon: "Solid-state drives are lightning fast and the technology is maturing quickly. At the moment, they make for luxury OS drives, providing quick boot and application launches, but are very expensive in sizes over 128GB. When working with large sample libraries or very high track-counts, users are often better off with more standard hard drives to spread the load, partitioned to only use part of the disk (the outer part of the physical disk provides much better performance then the inner). A dedicated RAID controller and a RAID5 setup offers performance and safety. For video work, it can make sense, but it isn't cheap.”

Pete: "Good-quality 7200rpm drives can still cope with most users' data requirements. Some users may feel that the added performance of expensive SSDs or the noise issues of 10,000rpm drives may outweigh the negatives, and indeed SSDs are popular for speeding up the operating system. Consider all the pros and cons before going for high‑performance options.”

Reliable Infrastructure

Specialist audio PCs tend to feature more expensive cases, extra acoustic treatment, high-quality PSUs, branded rather than generic RAM, and well‑known motherboard makes and models, all of which obviously pushes end prices up compared with mainstream models. However, many musicians still find it hard to believe that specialist audio PCs are any 'better' than cheaper mainstream models. I invited the experts to explain what sort of audio problems they've experienced while searching for suitable components for their own models, how easy they'd be for an average clued‑up PC user to solve, and how much of a problem it is trying to maintain supplies of tried-and-tested components while keeping abreast of the latest developments.

Simon: "We've had MOTU 424 cards not working with Gigabyte boards (we made people aware on the SOS forums, as it was such a severe issue), UAD cards conflicting with graphics‑card drivers, and multiple UAD cards needing a particular motherboard BIOS. To solve these requires time, components and knowledgeable staff. To validate our new releases we have to test a variety of motherboards and CPUs with PCI, PCIe, USB and Firewire interfaces, plus DSP cards. Throw 32‑bit and 64‑bit software into that mix and you start to see what's involved in getting an audio computer ready for the end user.”

Scott: "The sum is greater than the parts, but each part can be vital to stability. The most overlooked part is the power supply. Apart from low noise, both quality and wattage are key — 500W is a bare minimum, although I prefer 700W. An under‑volted/amped system can cause so many potential issues that will have you thinking it's all the other components that are bad. Motherboard choice would be next, particularly those who intend to add PCI/PCIe cards. I could write a complete essay on this! Quality motherboards will have compatibility and, equally important, excellent power management — particularly when it comes to the memory. Most motherboard issues stem from bad power management. This is also a moving target, as many manufacturers' quality control is lacking.”

Pete: "Higher-quality parts are chosen for their increased reliably and ensured stability. For instance, one part of the machine that often gets overlooked is the power supply. Good models will be able to output the quoted loads and total claimed power output with ease for prolonged periods, but it's not unknown for lesser-quality units to lead to random errors and system resets that may be difficult to track down, and in a worst-case scenario, a poor PSU can potentially cause damage other components if it eventually fails.”

Robin: "Sourcing our new Livebook laptop-based system, we tried a number of well known high‑end brands. Each was incapable of running audio interfaces successfully out of the box. After a lot of tweaking, we found one solution, but others simply would not work. That would be an expensive mistake for an average user! Each new generation brings more power and possibilities to the recording musician, usually for the same price as the last, so you have to move on.

"On the whole, the technology is good. Even Windows is awesome these days. But experience is the most valuable commodity when working with this stuff, as it will apply to all generations of technology, and there are always challenges.”

Conclusions?

As you can see, then, while the promising advances made in PC technology, such as fast multicore processors, faster RAM, solid-state drives and USB 3, are all welcome, they also mean that choosing the most appropriate components for an audio PC is probably more confusing than ever before! There are so many choices to be made, pitfalls to avoid, and new ways to eat up your budget.

While advances like Intel's Thunderbolt technology are keenly anticipated for future machines, the biggest excitement among audio PC builders currently seems reserved for systems based on Intel's new 'Sandy Bridge' processors — largely because they promise excellent audio performance while remaining reasonably affordable.

We've already got our hands on a Sandy Bridge system from one of the specialists involved in this feature for review, and in the fullness of time I'll follow this up with a more hands‑on DIY feature, based on my imminent experiences, which should appeal to those of you who want to build their own Sandy Bridge audio machine.