Crossfire motherboard roundup - 975X vs RD580! - Motherboard notes
Author: Vedran Dakic
Date: 10 Jun 2006

With MSI's 975X Platinum we didn't have any issues, but merely things we thought were lacking. The BIOS of this motherboard is a bit more "consumer" then we expected, it doesn't support DDR2-800 (DDR2-533 and DDR2-667), and you can't really lower the frequency of the FSB (only increase the frequency), so we tested with DDR2-667 with 4-4-4-12 timings.
With Gigabyte's GA-1975X there is also one thing we'd like to change. The plastic casing around the CPU is really frustrating if you want to put Zalman's cooler on the CPU. Although this casing is there to enhance the airflow, it really gave us headache. But as far as everything else is concerned there's no problem and this is - by BIOS standards - the richest of the three 975-based motherboards. BIOS settings include voltage regulation, MEM/FSB multipliers - and they all worked except the last one (4). So with 333x3.33 everything worked fine, but with 250x4 it was a no-go. We managed to overclock the CPU to 4.2 GHz (300x14) and everything worked with zero problems (of course, we used the water cooling system). What this motherboard also supports is DDR2-800, so we used DDR2-800 at 4-4-4-12 for our testing.
Foxconn's 975X7AA has a decent BIOS and features, and we really didn't have a single issue with her. It was very stable and all of the testing procedures worked without any problems.
We should point out that, although strange - we decided not to include the results of SiSoft Sandra tests. The reason is rather simple - all of the RD580 motherboard-based systems had a nasty habit of crashing every time you start testing with Sandra. ASUS's motherboard acted very strange in particular, with PCMark scores going insane (take a look at the PCMark HDD score). Also, if you thought this is bad, testing with Everest was even more fun. The first set of Everest tests gave us world-record-class results for Memory Read test, and the second run showed negative (yes, you're reading it right, negative) results. We exploited the BIOS up to a point where we went insane and found no solution. We can only hope that some future BIOS revisions will solve these issues. With Sapphire's and DFI's motherboards we didn't have any other problems, but DFI's motherboard really stands up front with all of the BIOS options.