Zotac's X58SLI-A-E
We had originally intended to include Zotac's X58SLI-A-E motherboard in this round-up, but it wasn't meant to be. The X58SLI just popped up for sale at Newegg, where it's listed at $199 with instant savings and a mail-in rebate that bring the price down to a tantalizing $170. That doesn't buy much in the way of frills and extras, but you do get dual PCI Express x16 slots with CrossFire and SLI support, six DIMM slots, Firewire, Gigabit Ethernet, and digital audio output, along the same X58 chipset as everyone else.

Unfortunately, the board's BIOS is a joke, at least from an enthusiast's perspective. Not only does it completely lack voltage options and overclocking controls, but you can't even adjust memory timings. At its factory defaults, the board wouldn't boot with three channels of the OCZ DDR3-1600 memory we use for Core i7 motherboard testing, either. Given that the OCZ DIMMs require 1.65V, it's not surprising that the Zotac board can only handle one of them at a time. Honestly, though, I couldn't see the point of digging into extensive troubleshooting.

These days, overclocking, voltage, and memory timing controls are staples of even low-end motherboards. Not having them present on a $200—or even $170—board based on a high-end chipset is simply inexcusable. We've asked Zotac when it expects to bring the X58SLI's BIOS up to speed, but have yet to hear back after more than a week. Clearly, PC enthusiasts should avoid the X58SLI. We'll revisit the board when its BIOS is compatible with the same hardware that runs without issue in the seven other Core i7 boards we've tested to date.

Our testing methods
In addition to pitting the EX58-UD3R, P6T, and X58 Platinum against each other, we're throwing them into the cage with a collection of much more expensive rivals. With all these platforms sharing the same chipset and a processor with an on-die memory controller, don't expect much difference in application performance. However, pay particular attention to the results of our overclocking, power consumption, and peripheral performance tests—that's where most of the gaps are these days.

All tests were run three times, and their results were averaged.

All of our test systems were powered by OCZ GameXStream 700W power supply units. Thanks to OCZ for providing these units and our DDR3-1600 DIMMs for our use in testing

Finally, we'd like to thank Western Digital for sending Raptor WD1500ADFD hard drives for our test rigs.

We used the following versions of our test applications:

• SiSoft Sandra Standard 2009 15.42
• WorldBench 6.0 Beta 2
• HD Tach 3.03
• Call of Duty 4 1.4
• RightMark Audio Analyzer 6.06
• NTttcp
• CASE Lab Euler3d CFD benchmark multithreaded edition
• Crysis 1.21
• Enemy Territory: Quake Wars 1.4
• Half-Life 2: Episode Two
• CPU-Z 1.41

The test systems' Windows desktop was set at 1280x1024 in 32-bit color at an 85Hz screen refresh rate. Vertical refresh sync (vsync) was disabled for all tests.

All the tests and methods we employed are publicly available and reproducible. If you have questions about our methods, hit our forums to talk with us about them.