Asus P5KC

Manufacturer:
Price:	£80.61 inc VAT
Reviewer:	Clive Webster
Review Date:	Sep 2007
Speed	40/45	89%
Features	24/30	80%
Value	23/25	92%
Overall	87%

Verdict: Asus solves the memory debate: use DDR2 now but be ready for DDR3 and Penryn.

With the computer industry's ever-changing standards, it's inevitable that there will be upgrade quandaries: do I settle for old technology that's cheap and does the job but will date quickly, or do I pay extra to buy the expensive new technology that promises so much? However, where there's a dilemma, there's usually a solution (note the proper use of 'solution' here, AMD, Intel and the rest). The main quandary when buying a motherboard at the moment - now that LGA775 is the obvious socket choice - is which type of RAM to buy. Hence this board, the second of the Intel P35 combo boards this month, which is compatible with both DDR2 and DDR3. As it's a P35 board, it will handle the imminent Penryn-based CPUs too.

Apart from its six RAM slots - two DDR3 and four DDR2 - the most obvious difference between this motherboard and other Asus models we've seen recently is the lack of extravagant cooling. You can use pretty much any CPU cooler, or replace the supplied heatsinks, without feeling that you're chucking away a small mine's worth of copper.

If you look at the picture of the board on the next page, you'll see a mostly excellent layout. The power connectors are on the edges to facilitate neat cabling, while the two high-speed PCI-E slots are widely spaced, with two PCI slots between them. If you're set on using two Radeon HD 2900 XTs, they'll have room to breathe, even if the poxy four PCI-E lanes to the second graphics slot is a performance bottleneck. The Asus Blitz Extreme and Blitz Formula (Issue 49, p39), with Crosslinx chips giving the second slot eight PCI-E lanes, are up to 13 per cent faster in CrossFire than any other P35 board.

The second 16x slot could be used with 1x or 4x PCI-E cards, which is worth remembering, as the board has only one 1x PCI-E slot. One of the three PCI slots would have to house a RAID controller if you wanted to create a disk array, as the Southbridge is the RAID-less Intel ICH9 rather than the more capable ICH9R.

The only real cause for concern is the odd placement of the EIDE connector on the bottom of the PCB. We've never seen an EIDE cable so long that it will stretch from the top front to the lower rear of a case. Asus clearly hopes that you'll buy a new S-ATA optical drive, given that such drives now cost less than £20. If that's the case, however, why include an EIDE port at all? Or why not swap the position of the nearly defunct FDD and the EIDE port?

This oddity is compounded by the lack of a PS/2 mouse port at the rear. At least Asus has a good excuse for this, as the rear I/O block is crammed with other stuff. There are six USB 2 ports, FireWire, eSATA, Gigabit Ethernet, both optical and digital S/PDIF outputs, and the usual six mini-jacks. There's also a further FireWire header and two USB 2 headers along the bottom edge of the board; no backplates are provided, but your case should be able to use them. A decent bundle includes a S-ATA cable for each of the four connectors (two have right-angled connectors, which can help to keep cables tidy), and two Molex-to-twin S-ATA cables to avoid incompatibility with an old S-ATA-shy PSU.

There's no mention of any silly 'dummy DIMMs' to force the board to use one memory type or another. With the P5KC, you slot in either memory type (it doesn't support DDR2 and DDR3 at the same time), and the board works. However, the BIOS doesn't reset itself; if you switch from performance 2.4V DDR2 to 1.5V DDR3, you'll probably have a set of oversized £300 dog tags rather than usable high-frequency RAM.

Performance

The big question surrounding boards such as the P5KC is whether the core logic chipset has been compromised to achieve the extra memory compatibility. After all, one of the memory controllers in the P35 was always intended to be shut down.

The first set of benchmark results was poor, especially in the multitasking test. We updated the BIOS to revision 0701 (11 July), which boosted the scores considerably. The multitasking score leapt from 796 to 869, while the other tests resulted in the near-1,000 score we'd expect from a DDR2 P35 at stock speeds with our standard test kit. Clearly, Asus is still getting to grips with a combo P35, so performance may improve with later revisions.

A future BIOS revision should also address the memory glitches we suffered, as the P5KC was a terror when trying to run memory at high frequencies. We had to use the Auto setting with both DDR2 and DDR3, as trying to use the 1,066MHz of our Corsair XMS2 PC2-8500 - or even the 1,333MHz setting we tried with the Patriot PC3-15000 (1,866MHz) - made the system hang at POST. On one occasion, we had to use Vista's excellent MBR repairer, as the memory controller messed up the boot procedure. Stock tests therefore had to be conducted with the DDR2 at 800MHz and the DDR3 at 1,066MHz.

As with the MSI Combo, we still saw slow performance in the multitasking test, no matter which RAM we used - a problem with core logic if ever there was one. Switching to DDR3 increased stock speeds, but not by much.

Overclocking was as easy with the P5KC as with other P5K boards (and the MSI P35 Combo), no matter which type of memory we used. It easily pushed our Intel Core 2 Duo E6750 from 2.66GHz to 3.66GHz by boosting its vcore to 1.5125V. We didn't have to touch the Northbridge or FSB voltages, although the comprehensive BIOS has options for tweaking these. Pushing an overclock too far resulted in a system restart and an 'Overclocking Failed' message in POST, which let us re-enter the BIOS without needing to clear its values. The maximum FSB of 520MHz also seems to contradict the P5KC's low price. We achieved good Supreme Commander scores, although again this result could be due to the BIOS update, and therefore apply to other boards too.

In DDR2 mode, we saw a surprisingly high score after the overclock, with the multitasking test finishing particularly quickly. In fact, when fully overclocked, this board was faster than the DDR2, P35-based Blitz Formula. This could be due to the new BIOS, but it isn't bad for a board that's roughly half the price. When we switched to DDR3, most tests reacted well to the overclock, although the multitasking test remained sluggish. There's clearly more work to be done on the BIOS.

Conclusion

This motherboard is a combination of great and worrying. While the odd EIDE port and lack of PS/2 mouse support may put you off, the major issues are the performance hit in the multitasking test and the memory controller's dislike for high-frequency RAM. However, you may feel that memory overclocking is only the icing on the CPU-overclock cake, and that you can live without expensive performance RAM if you can add 1GHz to your CPU. The P5KC is capable of big overclocks, and with these applied, it matches boards that cost twice as much for speed.

The issue of the flaky memory controller is mitigated by the low price, and the type of product this is; you'll only buy this if you plan to upgrade to DDR3 next year, by which time it may have a more robust BIOS. More importantly, DDR3 will be cheaper and may deliver good performance at fairly low frequencies (we'd hope for 1,333MHz at least).

The main advantage of buying this board is that you needn't agonise over whether DDR3 is worth buying now - buy the P5KC and you won't have to replace it next year as you might do with a DDR2-only P35 board. It gives you peace of mind and resolves the memory dilemma. Best of all, it doesn't cost a fortune and overclocks well.