Lab

Intel motherboards

[PC Pro]

Whether you're upgrading your existing PC or building one from scratch, the motherboard you choose is of critical importance. Make the wrong decision and you could be left behind when the next generation of hard disks, graphics cards and memory hits the market. This comprehensive Labs highlights all the most important issues, from which processor to choose to the optimum memory for your system.
For many, the first decision is whether to use an Intel or AMD CPU. That's why we've produced our definitive test of processors with a stunning 29 chips put through our benchmarks. Then there's the chipset. This determines support for memory types, AGP 8x graphics cards, USB 2 and much more. As well as giving a guide to each chipset's features, we test their speed in both 2D and 3D.
But there are plenty more decisions to be made beyond the processor and chipset. Factors such as expansion potential, integrated components, memory type and even overclocking options must be weighed up, as they all differ from board to board.
While purists may still consider integration to be a dirty word, we were surprised at the high quality of integrated components. The majority of motherboards have six-channel audio - adequate for all but the most demanding users - and 10/100 Ethernet. In addition, several feature built-in Ultra ATA RAID, Serial ATA and Gigabit Ethernet.

Guide to processors:

The definitive guide to all the Socket 478 Intel and Socket A AMD chips currently available:
Intel's offerings
Intel currently has two types of desktop processor on the market: the Pentium 4 and the Celeron. The Pentium 4 started life as the Willamette core and came in 1.4GHz and 1.5GHz flavours - far surpassing the Pentium III, which struggled to reach 1GHz. It featured a brand-new architecture called NetBurst. One of the key factors was the Hyper Pipelined Technology, which doubled the number of pipelines stages to 20.
The processor pipeline is where the x86 instructions are executed and is split into a number of stages, each of which carries out a certain portion of the work. However, the fewer the number of stages, the greater the amount of work each stage has before it completes, resulting in latency. This latency restricts the maximum speed of the pipeline, and hence the CPU speed.
By using 20 stages, Intel spreads the work more thinly, reducing the latency at each stage and allowing for far greater clock speeds. There are disadvantages too, and executing fewer instructions per stage also means the CPU does less work per clock cycle than, for example, the Pentium III. One way round this is to make the pipeline more efficient, and Intel attempts this by allowing for six instructions to be in the pipeline at any one time, which can be executed out of order.
The CPU also attempts to predict what instructions will be required next, but there will still be times when it 'mispredicts'. In this case, the instruction is flushed and another is loaded - depending on where it was in the pipeline, this can severely affect performance. Intel recognised this and, as well as optimising a small Level 1 cache, added a cache to store micro-ops (basically decoded instructions) ready to feed into the pipeline.
To compensate for the loss of performance due to mispredictions, and also to bring the Integer performer to a competitive level, Intel ran the Pentium 4's ALUs (Arithmetic Logic Units) at twice the speed of the CPU. It also introduced a quad-pumped FSB for communications with the memory and north bridge - this means it transfers data four times per clock cycle. Another change was the new SSE2 instructions, adding further performance benefits in certain areas, such as multimedia applications and games.
The 1.4GHz and 1.5GHz Willamette-based Pentium 4 CPUs used a 100MHz front side bus (FSB) - effectively 400MHz - and were built using a 0.18-micron process, but performance was poor. Intel trailed AMD up until the release of its second Pentium 4 core, named Northwood, which included two changes. The first was a move to a 0.13-micron process, enabling higher frequencies at lower voltages and with less heat. The second was an increase to 512Kb of Level 2 cache, compared to 256Kb. A further revision, called Northwood B, added a 133MHz FSB (effectively 533MHz), broadening the bandwidth significantly.
Intel recently introduced a minor revision to the Northwood core to incorporate Hyper-Threading. This is Intel's new technology, introduced with the 3.06GHz Pentium 4, which fools Windows XP into thinking there are two processors inside your PC - it's similar to SMP (symmetrical multiprocessing). However, SMP is only useful if you use your computer for large amounts of number crunching, and even then you'll need to use apps designed to take advantage of more than one processor.
The Celeron is based on the Pentium 4 Willamette core, but features only 128KB of Level 2 cache. The 2GHz and higher Celerons are also built using the latest 0.13-micron process and, although they perform comparatively poorly against the Pentium 4, Celerons can be significantly overclocked.
The Athlon XP
When AMD first announced its decision to use an equivalent rating for its XP processors, it met with a cynical reaction from the press. However, the test of time has proved AMD right. Despite being clocked at just 2.17GHz, the latest Athlon XP - named 3000+ - is more than a match for the 3GHz Pentium 4 (although AMD claims the model number refers to how the equivalently clocked Athlon would have performed, not a Pentium 4).
The reason a 2.17GHz chip can perform on a par or faster than Intel's 3GHz chip is their different architectures. As explained earlier, the Pentium 4's deep pipeline allows for higher clock speeds. Conversely, the Athlon XP features a ten-stage pipeline, meaning each stage is more complex and therefore executes more slowly. This has benefits too - the main one being that each stage executes more instructions.
However, efficiency is just as important, and this is where AMD's Quantispeed architecture comes in to play. The Athlon XP can have nine instructions in the pipeline at one time and features powerful pipelined floating-point units - serious number crunching.
There's also technology to keep the CPU fed with data, such as the Hardware Data Prefetch, which looks for regular memory access patterns and loads the data into the Level 2 cache in advance of it being accessed. This reduces latency, as the CPU would otherwise need to fetch data from main memory, which takes longer. There's also a Translation Lookaside Buffer - essentially an index of recently accessed pages of memory - which helps reduce delays in the event that a required instruction isn't stored in the cache memory (a cache miss). It also features AMD's 3DNow! Professional technology, adding 3DNow! and SSE (not SSE2) instructions to accelerate certain apps, such as games and multimedia.
However, AMD still needs high MHz to compete, and to achieve this it has had to revise the Athlon XP core several times. The first Athlon XP (codenamed Palomino) was built using AMD's 0.18-micron process and included 128KB of Level 1 cache and 256KB of Level 2 cache. Like the Thunderbird core before it, the 'Palomino' used a 266MHz FSB, but could run at much faster speeds - the fastest being 1.73GHz for the XP 2100+.
After the Palomino core hit its limit, AMD transitioned to a 0.13-micron Thoroughbred core, which allowed for faster speeds using less power. It also made some architectural changes to help it cope with the higher clocks. This allowed for some extra headroom and speeds up to 1.8GHz (Athlon XP 2200+).
Taking this higher required a second revision of the Thoroughbred core (Thoroughbred-B), which added support for a 333MHz FSB and boosted speeds up to 2.17GHz (XP 2700+). Most Athlon XP processors are now based on the Thoroughbred-B core.
The latest and probably final revision to the XP core is codenamed Barton. This is essentially the same as the Thoroughbred-B, but with 512KB of Level 2 cache as opposed to 256KB. This means AMD can give its chips higher model numbers, but actually reduce the frequency. In fact, the 1.83GHz Athlon XP 2500+, which is based on the Barton core, is almost as fast as the 2.17GHz XP 2700+, based on the Thoroughbred-B. Apart from the XP 2500+, only the 2800+ and 3000+ are currently based on the Barton core.
Into the future
Unfortunately, there's no such thing as future-proofing your PC anymore (if there ever was). If you buy the top-of-the-range Athlon XP or Pentium 4 today, the next big step will be either the Athlon 64 or the Prescott-based Pentium 4. And neither of these will work with any of the motherboards reviewed here. In the near future, it looks like Intel will release a 3.2GHz Pentium 4 and AMD will release an Athlon 3200+ chip (based on the Barton core). But that's it.
Intel has recently revealed more details about the Prescott - Northwood's successor. Features include a 16KB Level 1 cache (up from 8KB), 1MB Level 2 cache, 0.09-micron die and 13 new instructions. Another key change is the 200MHz FSB, which is quad-pumped to give an effective speed of 800MHz. Naturally, there will be new chipsets to accompany the processor too.
AMD has also already announced the successor to the Athlon XP: the Athlon 64. This will use 64-bit technology instead of the 32-bit system in current mainstream chips, but it will be backwards-compatible with 32-bit software. Microsoft hasn't yet committed to a date for its 64-bit version of Windows on the desktop, but hopefully the companies will release products at the same time: September 2003.
PERFORMANCE
Enough theory. We wanted to see how all these chips performed in our real-world benchmarks, and so we set to testing them - every single chip that you can buy today. We used the same Crucial PC2700 memory (512MB split across two DIMMs) and Western Digital hard disks as we do for motherboard testing. To test the AMD chips, we used Gigabyte's 7VAXP Ultra, which is based on VIA's KT400 chipset. To test the Intel chips, we used Gigabyte's SINXP1394, which uses the SiS655 chipset.
As you can see from the graphs on the right, the 3.06GHz Pentium 4 (with Hyper-Threading turned off) was the fastest CPU in both 2D and 3D. However, we also calculated the processors' scores for value for money (using a weighting of their 2D and 3D performance results combined with the cost of the chip). Here, AMD won most kudos, with all of its range up to the Athlon XP 2500+ offering excellent value for money. See www.pcpro.co.uk for a full breakdown of the results.
The VIA alternative
To conclude this round-up of processors, we shouldn't ignore the VIA C3 chip. VIA has just released a 1GHz version and allowed us a first-look at it in action. In terms of performance, it's certainly no match for the latest Athlon XP or Pentium 4 chips - the 1GHz chip only scored 0.46 in our tests - but it can still handle everyday tasks. Most importantly, it can handle DVD video (especially in tandem with the Apollo CLE266 chipset, which includes a hardware MPEG-2 decoder).
It has other advantages over the big two as well. First, VIA has introduced a hardware random number generator in the CPU to protect your data. Second, it doesn't need much power to run, which means less heat and less noise.