ECS PF88 Extreme and A9S SIMA card Grange-over-Sands

Children don't learn enough facts at school these days. What 21st-century ten-year-old can tell you what the first battle of the War Of The Roses was, or when King Ethelwulf reigned?* If school kids had a sample PF88 to play with, they'd learn facts such as these in no time, provided you could also convince Microsoft to use Windows XP keys that contained historical information. This is because installing Windows on the PF88 is a tricky and laborious business, requiring you to restart frequently and enter the product key many times over. But it worked for me; I now know the Custom PC Windows XP key off by heart. Backwards. Just imagine if that key wasn't simply a random string of numbers and letters; how much more useful would it be if it contained the date of the Glorious Revolution or a brief rundown of the causes of World War II?

Microsoft's XP keys might lack the ambition to transform the learning process, but the ECS PF88 Extreme (to give the motherboard its full name) certainly isn't short of determination. The PF88 Extreme is upgradable. ECS has added an Elite Bus slot to the board, into which you can insert a 'SIMA card,' which will make the LGA775 PF88 Extreme compatible with any number of other CPUs.

We tested it with the A9S SIMA card, which features a Socket 939 mount for Athlon 64 CPUs, although ECS is promising Pentium M and Socket 754 Sempron SIMA cards in the future, as well as one featuring AMD's forthcoming M2 socket.

Without a SIMA card, the PF88 Extreme is a 'normal' Intel motherboard, with an LGA775 socket at the top, a Northbridge, Southbridge, and a selection of PCI and PCI-E slots. Add the SIMA card and suddenly the LGA775 socket is redundant, as the SIMA card has its own 939-pin socket for Athlon 64 chips, a cluster of capacitors and an ATX 12V power connector. The Athlon 64 SIMA card also has its own two DDR DIMM sockets, as the PF88 Extreme uses DDR2 RAM in Intel mode.

On the flipside of the A9S SIMA card lurks a spiky silver heatsink of the kind that normally cools a Northbridge. As all Custom PC students know, the Athlon 64's integrated memory controller effectively negates the need for a Northbridge - so what's the SIMA card hiding?

In Intel mode, the PF88 Extreme uses the Northbridge to control not only the DDR2, but the 16x PCI-E slot too. These are both turned off when the SIMA card is in use, so the A9S has a Northbridge chip to control a 16x PCI-E slot. All these chips are supplied by SiS; in Intel mode, the PF88 uses a SiS 656 Northbridge, with a SiS 965 Southbridge, while the A9S SIMA card replaces the SiS 656 with the SiS 756.

The SiS chipset offers a reasonable range of features in Intel mode, including support for Intel's dual-core chips. Although there are two 16x PCI-E slots, dual graphics cards aren't supported; one of these slots is reserved for use when the SIMA card is fitted.

There are also two PCI slots and a single 1x PCI-E slot. Of the six S-ATA ports, two are S-ATA II, which will provide fast data transfer speeds from yet-to-be-released hard drives. The two S-ATA II ports run from the Southbridge and are RAID-capable, while a Silicon Image chip provides the remaining four, which also support RAID. One benefit of the PF88 Extreme not using Intel core logic is the improved support for EIDE devices, with two EIDE ports. The downside is the on-board audio: it might be 8-channel, but it's still of the basic AC97 variety.

If you decide to use the A9S card then the sound and ports remain almost identical, although you'll have to use the second 16x PCI-E slot for the graphics card, as the first one is blocked off by the SIMA card. So is switching from a Pentium to an Athlon 64 really as simple as inserting a PCB? Is becoming King just a matter of waiting for the current monarch to pop his or her clogs? Sadly, experience teaches us that the answer to both these questions is no. Getting the SIMA card working doesn't quite require the kind of machinations in which Richard III specialised, but it's still pretty tricky. Firstly, you have to remove 22 little jumpers from either side of the Elite Bus slot. Then you have to prise the two BIOS chips out of their sockets, and insert one into the correct socket. Bizarrely, while the PF88 Extreme will work in Intel mode with two BIOS chips inserted, with the A9S card, you can't fill the second BIOS chip socket.

This done, you then need to unplug the ATX 12V wire from next to the LGA775 socket and plug it into the A9S card. This simple task is made very tricky by a component situated right next to the 4-pin plug near the Intel socket, which blocks the power wire's release catch. Once you've managed to prise the wire away from the board's rigor mortis grip, then you're ready to go. The final SIMA caveat is that the width of the A9S PCB is obviously limited, and as you also have two DIMM sockets on there, there isn't a lot of room for an Athlon 64 heatsink.

Our standard test HSF, the Arctic Cooling Freezer 64, didn't fit, as it bumped into the heatsink on the Intel side's SiS Northbridge. We were confined to using the noisy AMD reference HSF. Also, despite the fact that both the Intel and AMD sides use SiS chipsets, you'll still need to reinstall Windows XP when you switch.



PERFORMANCE

Once you've performed this ceremony, however, it actually works. The PF88 Extreme hums into life, with the Athlon 64 HSF sitting so close to the LGA775 socket that it's blowing hot air right onto the pins. It's an impressive sight and proves that motherboards are more modular than most people think; there's enough continuity and shared genes to be able to chop and change sockets without needing a complete motherboard redesign.

We tested the PF88 Extreme in Intel mode using a dual-core Pentium D 820, clocked at 2.8GHz, so we couldn't compare the ECS board with those tested in last month's motherboard megatest. However, pitted against Abit's Intel 945P-powered board, the PF88 Extreme performs relatively poorly - clearly Intel knows a lot more about getting good performance from a Pentium D than SiS does. The Intel chip overclocked fairly well, though, despite the fact the BIOS uses a clunky divider system for setting RAM speeds. Running our DDR2 at a 3:4 ratio, the PF88 Extreme successfully benchmarked with a 240MHz FSB, which would have placed it near the top of the list of last issue's Intel boards.

However, it was the Athlon 64 testing we were most interested in - surely the Elite Bus would slow it down? Surprisingly, the answer was no: in our Media Benchmarks, the PF88 Extreme with the A9S SIMA card actually took the Nvidia nForce4-powered motherboards from last issue to school, as it beat them (slightly) in all three benchmarks. Once the PF88 Extreme is working, it flies along. Gaming performance was a frame or two below par, but the PF88 Extreme wasn't miles adrift.

Overclocking with the A9S was disappointing, however; the Athlon 64 BIOS is barer than a monastery after a visit from Henry VIII's goon squad. There's no support for changing the multiplier, even though the chip is unlocked, no voltage controls, and you can only take the FSB values up to 232MHz. As it was, the highest FSB we could achieve was a miserable 205MHz. This part of the project deserves plenty of red pen.



CONCLUSION

While the SIMA card might look odd and clunky, in terms of performance, you lose nothing from routing the processor through the Elite Bus slot. Technically, the PF88 Extreme is a marvel. However, for all its technical prowess, there's no getting away from the fact that switching modes is extremely hard work. Activating the Elite Bus slot is a royal pain in the neck - why on earth is it necessary to have 22 separate jumpers? The BIOS chip fandango you have to perform is tricky too, and even when we got our board working, there were still issues: it wouldn't work with Corsair DDR2 RAM, and had trouble saving changes to the BIOS and then rebooting. Of course, these problems could just be gremlins in our particular review board.

At stock speeds, the SiS chipset didn't prove to be any good for the Intel CPU, but things were much rosier on the AMD side. It's a shame that the A9S BIOS wasn't more fully featured, as the main motherboard PCB wasn't resistant to overclocking. As you can see from the price, the PF88 Extreme is, thanks to its SiS heart, pretty cheap, as is the A9S card. As with all history, though, once the facts are over and the battles settled, the question that remains is 'why did this happen?' Who is going to change from an LGA775 Pentium CPU to an Athlon 64? Some people might be attracted by the money-saving potential of not needing to upgrade when a socket comes along, but they'd surely be put off by the technical pomp and ceremony that the PF88 Extreme requires.

There's something here for experimentally minded, technically savvy people. If you fancy being able to try out CPUs then the PF88 Extreme is an interesting proposition. You'd have to be fairly well off, though, because while SIMA cards are commendably cheap, CPUs aren't.

The PF88 Extreme has more than its share of flaws (the BIOS doesn't have enough features, and there are stability and speed issues on the Pentium side of things), but it has a glimmer of potential. Perhaps it will be the start of an interesting dynasty of modular enthusiast motherboards.

Author: Alex Watson

ECS PF88 Extreme and A9S SIMA card