If you thought the MMX processor was still the last word in new technology, prepare to boldly go where your PC has never gone before. Martin Walker looks at the many new families of PC chips, and explains their relevance to the musician.
So many new PC processor chips have been released during the last year that it's not surprising if many people are a bit confused. Almost everyone has heard about the Pentium MMX processor, particularly due to the controversy that followed its inauspicious launch directly after Christmas 1996. However, despite the promises of huge potential increases in performance, little software uses its powers directly even now, and still less of this software is relevant to PC musicians. Fortunately, most applications that are not specifically written to take advantage of the special facilities of MMX still show a typical 10% system speed improvement when run on an MMX system, compared to a system using a non‑MMX chip of the same clock speed, largely due to the MMX's larger on‑board cache size and design. For this reason, although Cubase VST does not require an MMX processor, its designers claim a 10‑15% increase in performance if you have one installed. One application that does use MMX directly is Seer Systems' Reality software synth (which I reviewed in the November issue), and this shows a 30‑40% improvement with MMX, over the same speed of non‑MMX processor.
With the launches of other processors to rival the Pentium range, Intel have now removed the non‑MMX ones from the current line‑up. This leaves the Pentium 166MHz MMX as the entry‑level model, with a new low price of about £100, so if you still haven't got one in your PC, it's well worth upgrading. Check first with your supplier that your motherboard supports the MMX processors directly (they need a 2.8V supply, rather than the 3.3V supply used by their predecessors). Most bought in the last 18 months should do so, and in this case you can just use a standard MMX processor. If not, you'll need an MMX Overdrive upgrade, which is a bit more expensive (see June's PC Notes for full details).
Most people agree that, of all upgrades, installing a new motherboard is the most fiddly.
Since the Pentium 166MHz and 200MHz MMX models were released, they have been joined by a 233MHz model. Although many motherboards can run this one too, the faster the processor, the more current it takes, and some motherboard power supplies have insufficient 'welly' to cope — check your motherboard manual before purchase. Current prices are around £200 for the 200MHz chip and £300 for the 233MHz version. Don't buy a faster processor thinking that upgrading from a 166 to a 200MHz version will immediately give you a 20% improvement in overall system performance (200/166), because it doesn't work like that. Although the processor will be running 20% faster — and I have certainly measured this improvement when running DMSS plug‑ins — the processor is only one link in a long chain of components inside your PC. Expect a real‑world system improvement of more like 5% when upgrading from 166 to 200, and another 3‑4% when moving from 200 to 233.
The other big processor launch from Intel this year was their Pentium II range, which is designed to succeed the Pentium Pro. The Pro traditionally had a 'professional' image, with support for multiple processors on the same motherboard for more power. It is generally acknowledged that the 233MHz Pentium MMX is probably about as fast as standard Pentiums are likely to go (although there is an AMD K6 model running at 300MHz), but the Pentium II range starts at 233MHz (around £400), with faster models at 266MHz (£500) and 300MHz (£650). They all incorporate the benefits of MMX technology but, in a complete departure from all previous designs, the 'II' is not just a plug‑in chip, but a complete sub‑assembly with cache memory and a huge attached heatsink, which is known as the 'Slot 1' format. This requires a completely new design of motherboard, leaving existing Pro owners with no plug‑in upgrade path.
When it comes to other processing contenders, such as the K6 range from AMD, and the MX range from IBM/Cyrix, despite their MMX features (licensed from Intel in the case of AMD, and 'reverse engineered' with Cyrix) these are best avoided by musicians. When measuring audio performance with the majority of musical applications, my experience to date suggests that, despite their lower prices, the supposedly faster performance with mostmainstream applications simply does not translate to the rarefied world of HD audio and real‑time plug‑ins. Seer Systems measured the performance of their Reality software synthesizer: compared with their benchmark Pentium 200 (non‑MMX), the Pentium 200 MMX came in at 133%, the AMD K6 233 at 92%, and the Cyrix MX200 (166MHz) at less than half the speed (46%). Incidentally, the Pentium Pro 200 measured 200%, and the Pentium II 266 came in at a staggering 273% — nearly three times the speed. When it comes to music applications, it pays to have Intel Inside.
Although many people have no idea what sort of motherboard they have inside their PC, anyone buying a new machine (or those DIY‑ers who are happy to upgrade the more complicated bits) will need to know the options. Each motherboard is designed around one of several chipsets, consisting of between two and four Integrated Circuit chips, and most often designed by Intel (although there are several other manufacturers). The chipset used by your motherboard will determine the range of processors that you can plug in, the types of memory that can be used, and the hard disk performance.
The most significant choice is the processor, and for the majority of musicians at the moment this will normally be one designated as 'Socket 7'. Many processors will plug into a Socket 7, including all Pentiums, the AMD K5 and K6 ranges, and the IBM/Cyrix 6x86 and 6x86MX ranges. The 'Socket 8' standard is for plugging in Pentium Pro chips, but these have already been superseded by the Pentium II range, using the new 'Slot 1' format. These are the basic three choices for a motherboard, and each processor socket standard is supported by one or more chipsets. The chipset controls the flow of data to and from the components in your PC, such as the CPU, memory, hard drive, and any devices connected to either the ISA or PCI buses. Although a few motherboard manufacturers use chipsets from SIS, VIA and Opti, the majority rely on Intel's Triton series of chips.
The first chipset released by Intel for the Pentium was the 430FX (commonly known as the 'FX' or Triton). This has been superseded, first by the double launch of the 430HX and 430VX chipsets, and more recently by the 430TX. Most people probably have either HX or VX chipsets in existing PCs. The HX was also known as 'Triton II' (the 'H' is often referred to as High quality), and it offered increased support for up to 512Mb of RAM, as well as for dual processors. The 430VX (aka 'Triton III', and also referred to as the 'Value' model) has one advantage over the HX chipset: it supports up to 64Mb of SDRAM (Synchronous Dynamic RAM — see 'Thanks for the Memory' section, later, for more detail). Both HX and VX series perform about 10% faster than the previous FX chips.
The latest TX chipset, which appeared in mid‑1997, is supplied with most Socket 7 PCs sold today, and includes support for SDRAM (like the VX). More significantly, it also supports Ultra DMA/33 hard drives, which have a significantly better performance than their forbears. Finally, the TX chipset is often quoted as being optimised for MMX processors, although this is untrue — only software using the extra MMX processor instructions will show a major benefit, and this does not rely on any component on the motherboard.
If you are using a Pentium Pro or Pentium II, the relevant chipsets are the 440FX (Natoma) and the 440LX. The more recent LX is the only one of the two to support SDRAM and Ultra DMA/33, along with the latest feature — AGP (Accelerated Graphics Port). This allows users of heavy‑duty 3D graphics to move vast quantities of graphic data at a much faster rate than the normal PCI bus allows (33MHz). AGP runs at 66MHz in its basic 1x mode, and links the main memory to that of the graphics card for faster throughput. The 2x mode achieves an effective clock speed of 133MHz, but both modes need a special AGP video card which fits in a new design of card slot. Frankly, few musicians are likely to benefit from AGP.
Although good motherboard design is vital for top performance, you are unlikely to see more than a 5% variation in overall performance between different models. This is not to be scoffed at, but expandability is far more important. Your choice of PC motherboard will determine the number of available slots for expansion cards and memory upgrades, and for a musician this is just as important as the final few percent of overall speed.
Some motherboards are already showing a tendency to reduce support for the older ISA cards ""There does seem to be genuine evidence that occasional random PC crashes can sometimes be caused by cheap RAM running 'on the edge'.
One of the decisions facing manufacturers of expansion cards is whether to use the ISA or PCI bus. ISA (Industry Standard Architecture) has been around for a long time now — IBM expanded it from an 8‑bit to its current 16‑bit width in 1984, when it introduced the 80286 processor. Nowadays the bus is still being used a great deal, even byrecently introduced expansion cards (both DAL's V8 and Digital Wings' soundcards are ISA‑based), but many believe its days are numbered. This is partly because of its lower maximum data rate. Most modern Pentium processors operate with a system speed of 66MHz, with the other computer buses synchronised to this. The processor itself works at a fixed multiple of the system speed — so, for instance, a 133MHz device works at 2x the system speed, a 166MHz at 2.5x, a 200MHz model at 3x, and so on.
The 16‑bit ISA bus, which runs at a usual speed of about 8.25MHz, has a maximum data rate of 16.5Mb/second. This might sound huge, but PCI runs at 33MHz (half the speed of the motherboard) and has a 32‑bit width, which equates to 132Mb/second! Another major benefit of the PCI specification is that it can operate concurrently with the main PC processor — the CPU can be processing data while the PCI bus is busy transferring data between other parts of the system. One of the attractions of the PCI bus to manufacturers is that it is cross‑compatible with the Apple Mac; any PCI card should (theoretically) work on both platforms, as long as it has driver software available for each.
Although both buses can move loads of audio channels about (each mono 44.1kHz channel only requires 88.2Kb/second for a 16‑bit audio signal), the faster the data can be shifted, the better. Nearly all modern graphics and hard disk controller cards are PCI for maximum performance, with the ISA bus being used for devices that don't need so much bandwidth, such as stereo soundcards, MIDI interfaces, and modems. Multi‑channel audio cards tend to be of the PCI variety, especially since many sport DSP chips that can be used to offload some of the number‑crunching from the PC's main processor, for real‑time EQ and effects.
Some motherboards are already showing a tendency to reduce support for the older ISA cards; although you can still buy a large variety which have four each of ISA and PCI card slots (with one being shared, giving a total of seven simultaneous slots, which can be used as 4+3 or 3+4), some new motherboards are only supplying two ISA slots. Since many musicians are struggling to find space for all their existing ISA cards, this is something to watch out for when buying a new PC. In fact, Intel expect ISA‑based audio to be generally phased out by the end of 1998, since it is more limited than PCI and is less configurable and manageable as well.
Ultimately, the PCI bus speed will increase still further. Although some motherboard chipsets already allow the 66MHz motherboard speed to be increased to 75MHz or even 83MHz, Intel do not guarantee their chipsets when running at these greater speeds, and you can run into other problems, since your expansion cards will still be running at half motherboard speed, and therefore beyond their rated spec. As the PCI bus speed rises to 37.5 and 41.5MHz respectively, reliability of the cards may be reduced, or some may refuse to work at all. Intel's new AGP architecture (mentioned in the motherboard section) allows graphics cards to run at the full speed of the motherboard, and even at double speed, but unless you are running heavy 3D graphics you are unlikely to see significant system improvements. The big push will come next year, when Intel introduce their Slot 2 (successor to the Slot 1, as currently used by the Pentium II), which will have a 100MHz PCI bus speed.
When it comes to RAM, it's worth stressing how much better most Windows 95 PCs will perform with 32Mb rather than 16Mb. I noticed a huge difference when switching between applications after upgrading, since ideally Windows 95 likes to have 16Mb all to itself, and once you run an application you need more memory, so something has to be temporarily ferried off to the hard drive, to make more room. This allows you to run lots of applications, even when you have run out of 'real' memory. The technique is known as virtual memory, with the portion of the hard drive used called a swap file. Once you have 32Mb of RAM, your swap file will remain fairly small, so switching between applications will become much faster.
However, the latest applications, such as Cubase VST, require a minimum of 24Mb of RAM, to provide all the memory buffers that allow so many channels of audio to be used. If there's one thing I've learnt over the years it's that when a minimum is mentioned, you will nearly always get significant benefits by doubling it. The amount of RAM recommended for Cubase VST is 32Mb, but on my system (which has 32Mb) only about 5Mb is left after I launch VST, so if you want to run another application (such as an sound editor, librarian, or software synthesizer) you'll soon be back into virtual territory. I'm going to upgrade to 48 or even 64Mb in the near future.
When it comes to memory types, there are two main packages: SIMMs and DIMMs. Modern SIMMs (Single In‑line Memory Modules) have 72 pins and are used in pairs of the same value (for instance, a pair of 16Mb SIMMs will be needed for a 32Mb upgrade). Since most motherboards only provide four SIMM slots in total, this only allows you to upgrade once. However, popular SIMM sizes include 8, 16 and 32Mb, allowing you to install 16, 32, or 64Mb per pair respectively. DIMMs (Dual In‑line Memory Modules), as their name suggests, provide the equivalent of two SIMMs in a single convenient 168‑pin package. However, many motherboards only provide two DIMM sockets, so you are little better off when upgrading than with the SIMM type, although different sizes can be mixed at will.
Many motherboards provide both SIMM and DIMM sockets for memory, but few allow both types to be mixed, as memory must be installed in 'banks', and in most cases the SIMM and DIMM sockets are connected to the same banks, providing 'either but not both' support. Some only have SIMM sockets, but more of them (as many as eight in some models), and others only have DIMM sockets. You may even find a particular design of motherboard available in different versions, with either three DIMM sockets, or two DIMM and four SIMM sockets. Most of the time, therefore, the decision on which memory type to use when upgrading is taken out of your hands.
What's more important is that you match the speed of your memory upgrade with that already installed. Most modern PCs use EDO RAM, and this can be bought in three speeds: 70ns, 60ns, and 50ns. Don't ever buy 70ns, as this is too slow to work with any processor running at 100MHz or faster. If your machine has a 66MHz bus speed (100, 133, 166, 200MHz processors), you will need 60ns RAM, although some new motherboards can support the more expensive (and difficult to obtain) 50ns variety. Although you could mix 50ns RAM with existing 60ns memory, you would still have to run it all at the slower motherboard speed settings, so there's no real point in doing this. Also, much like the recent news in SOS that sampler RAM quality is definitely important, there are many reports on the Internet that, in PCs which have been tweaked to be even faster than normal, quality 60ns RAM tends to be more reliable than cheap 50ns RAM; there does seem to be genuine evidence that occasional random PC crashes can sometimes be caused by cheap RAM running 'on the edge'.
More esoteric memory choices, such as EDO (Extended Data Out) or SDRAM are, again, largely determined by the motherboard design. Unless you're contemplating buying or building a new machine, the only time you'll need to find out the type your motherboard is already using is if you want to add more RAM, as 'mixing and matching' is rarely an option. It's probably true to say that EDO RAM is currently fitted in the majority of modern machines (either in SIMM or DIMM packages), with SDRAM starting to appear more in higher end PCs (always in a DIMM package).
Many people think that SDRAM is the way forward, because although it currently costs more than other types it has the potential to give better system performance with faster machines. However, at motherboard bus speeds of 66MHz, you are unlikely to see any real improvements in performance with SDRAM. Testing the same system with first EDO RAM and then SDRAM is likely to show no significant change with the VX motherboard chipset, though the latest TX chipset will probably show a small improvement, in the order of 2%. Another advantage of TX is that it allows you to use 64Mb SDRAM modules, as well as 128Mb EDO modules, both in DIMM format. When the new PCI bus speed of 100MHz arrives next year, SDRAM should become more important.
As always, if you want to buy now you have to weigh up your desire to future‑proof your system against what your wallet can actually stand. Since PCs are advancing in performance at such a rapid rate, you can adopt one of two approaches if you want to stay abreast of the latest technologies. Either you buy a complete high‑performance system for about £1500, use it for a year or two, and then sell it (or trade it in) and buy a completely new system, or you adopt a continuous upgrade policy — buy new components for your existing system as you need them. If you decide on the latter approach you'll probably end up spending a few hundred pounds, three or four times a year, to get more memory, a faster processor, a larger and faster hard drive, and so on. Eventually you're likely to need a completely new motherboard, but a local supplier can fit this for you if you don't want to take on the task yourself, and this will keep your system up to scratch for significantly longer.
When it comes to music applications, it pays to have Intel Inside.
Sadly, audio applications seem to be optimised for Intel processors so, as mentioned earlier, it's a bit dicey to save money by buying an AMD or Cyrix chip. If you want to stay future‑proof for a little while longer, and are considering buying a completely new PC, look at a Pentium II system and you should be OK for at least a year. Unfortunately, if you want to upgrade on a component basis, Pentium II processors bought by themselves are still very expensive, and as you would also need a new motherboard (another £200 or so) you'd be better off going for a complete system and selling your existing machine. However, for those with an eye for a short‑term bargain, the Pentium Pro 200MHz is still 50% faster than the Pentium MMX 200MHz when running programs such as Reality, so as long as you don't mind having to upgrade again within a year, you might just find one of these at an excellent price by early 1998. Bear in mind, though, that you won't get much for it when you come to upgrade again.
If you're seriously strapped for cash (aren't we all?), buy a system featuring a TX chipset on the motherboard and get the fastest Intel Pentium MMX processor you can afford. The TX chipset should carry on at least till the end of 1998, and is the final and best option for Socket 7 processors (unless the rival processor manufacturers come up with something to keep things going a bit longer). To be honest, although you could start preparing for the move to Pentium II by spending a little more to buy the faster SDRAM memory instead of EDO, it may be better to sell your complete MMX system when the time comes, to get a better price, and then start afresh. By the time Pentium II systems are below £1000, mass‑market pricing should ensure that the other components they use will have come down in price significantly as well.
Of course, no‑one is forcing you to upgrade; as long as your current system is fast enough to support the applications you want to run, by all means stick with it. However, the fact remains that major updates for each sequencer seem to occur about every 18 months or so, and it is likely that Pentium II systems will be required for efficient operation of state‑of‑the‑art software by the end of 1998.
There are several choices when it comes to the physical dimensions and layout (form factor) of a PC motherboard. The most common boards, up to now, have been based on the 'Baby AT' layout, which has caused some problems for musicians. I have one in my current PC, and since the main CPU is in line with the card slots, its heatsink and fan prevent me from plugging in more than one full‑length ISA expansion card (which is about 13 inches long). The mass of wiring attaching peripherals such as the I/O ports and floppy and hard drives to the motherboard also obscures the memory sockets, which makes it far more difficult to add more memory without unplugging everything.
To make things easier, a new design known as ATX has been available for about a year: this relocates the processor from the front of the motherboard to the rear and to the side, beneath the power supply. This allows full‑length cards to be plugged into every available slot and, even more usefully for musicians, improves the cooling system. Rather than sucking in air from the front of the case by using an extractor fan in the power supply (which means that most processors still need an extra heatsink‑mounted fan to blow air directly onto the processor, to keep it sufficiently cool), the ATX design reverses the process: air is pulled into the case by the power supply fan, then blown directly towards the adjacent processor. This means that many processors need no dedicated fan of their own, which removes a major noise‑producing component from the studio environment.
From the manufacturer's point of view, ATX assembly costs are reduced, because the I/O sockets are an integral part of the motherboard. The only thing to watch out for is that ATX motherboards require a special case equipped with a different power supply from that of the more common Baby AT board, but these are relatively inexpensive — see the 'Buying the Bare Bones' box.
I recently spotted a very useful upgrade from PC suppliers Novatech which might be useful to you if you have an older PC in dire need of a few improvements. Novatech are now selling a 'Bare Bones' system, in both AT and ATX formats, which consists of a midi tower case with power supply, TX chipset motherboard, and floppy drive. The AT system costs £116 and the ATX (which will probably be more suitable for most musicians) is £222.
Most people agree that, of all upgrades, installing a new motherboard is the most fiddly, so as this has already been done all you need to do is plug in the easy bits. To complete your system, you can either buy a full set of components from Novatech, or simply cannibalise the majority of parts from your previous machine. These include the hard drive, CD‑ROM drive, video card and RAM — although, in keeping with the latest trends, the motherboard only has DIMM sockets, so this is your opportunity to upgrade to the latest SDRAM (see main text). Of course, you can carry on using your old monitor, keyboard and mouse. Finally (and the main reason for your upgrade), you can plug in a faster processor, such as a Pentium 200MHz MMX.
Novatech Bare Bones System £116 (AT) or £222 (ATX) including VAT.
There seems to be a general consensus that the current Socket 7 system, with a 66MHz PCI bus, will support processors up to 300MHz, but no further. Currently the favourite multimedia systems are favouring Pentium 200MHz MMX, or AMD K6 processors at the same speed, although the K6 is not so useful for musicians, for the reasons given in the main text. The latest TX chipset is also likely to be the last one developed for this system. Certainly, industry pundits expect the Pentium II to take over in 1998, and for even the Pentium 200MMX to start to disappear about halfway through next year.
You can already buy a complete Pentium II 266MHz system for about £1600 including VAT, which points to prices of more like £1000 once we get into 1998. The beauty of the Pentium II is that it combines features of the Pentium Pro range (such as multiple processor support) with the MMX enhancements of the standard Pentium range that it will eventually replace. The next architecture for processors is called Slot 2 and features the 100MHz bus also mentioned in the main text. The working name of this processor is 'Deschutes' [also the name of a 1.6‑million acre forest in Oregon, USA — News Ed] and the launch model is planned for about the second quarter of 1998, with a 400MHz clock speed, and requiring a new chipset known as the 450NX. Faster versions of the Pentium II are also expected — a 333MHz version early in 1998, which will use the same 66MHz bus as the current Pentium II models, followed by 350, 400, and 450MHz versions, all of which will need the 100MHz bus of the 440BX chipset.