ASUS M2N32-SLI & Epox MF570SLI: AM2 Wunderkinder

Overclocking

Epox MF570SLI Overclocking Testbed
Processor:	AM2 4800+ (x2, 2.4GHz, 1MB Cache per core)
CPU Voltage:	1.5V (default 1.4V)
Cooling:	AMD Stock Heatpipe FX62 Cooler
Power Supply:	OCZ Power Stream 520W
Memory:	Corsair Twin2x2048-PC2-8500C5 (2x1GB) (Micron Memory Chips)
Hard Drive	Hitachi 250GB 7200RPM SATA2 16MB Cache
Maximum OC: (Standard Ratio)	250x12 (5x HT, 3-3-3-13) 3000MHz (+25%)
Maximum FSB: (Lower Ratio)	318 x 9 (4x HT, 3-3-3-13) (2862MHz, 2 DIMMs in DC mode) (+59% Bus Overclock)

Any board that reaches a 300 clock speed or beyond must be considered an excellent overclocker. The Epox reached 318 clock speed with a 9x multiplier and 250 at the stock 12x multiplier. The 570 is a simpler design than the 590 and it should be as good at overclocking, or better than, the 590. There is no logical reason both 570 boards we have tested top out around 315.

Both platforms use the most up-to-date 590 MCP, with a few items disabled or unimplemented in the 570 version. We are left to wonder if perhaps the maximum overclock of the 570 is being artificially limited so as to make the 590 more attractive? We have no hard evidence of this thought; we are just trying to understand why a simpler solution - which normally overclocks better - does worse with the MSI and EPoX 570 SLI boards.

Memory Stress Testing
Optimum tRAS

The Epox MF570SLI behaved like the Foxconn and ATI in tRAS memory testing. As a result all testing was performed at 3-3-3-13 timings. This provided the greatest bandwidth and the best stability.

Memory Stress Testing

The Epox board does not offer the fine granularity of memory voltage controls that the ASUS board provides, as you can only increase voltage in 0.1V increments. We would prefer at the very least 0.05 V increments, and even better are the 0.025V increments that ASUS, Foxconn and others offer.

Epox MF570SLI DDR2-800 Timings - 2 DIMMs (2/4 slots populated - 1 Dual-Channel Bank)
Clock Speed:	200MHz
Timing Mode:	800MHz - Default
CAS Latency:	3
RAS to CAS Delay:	3
RAS Precharge:	3
RAS Cycle Time:	8
Command Rate:	2T
Voltage:	2.2V

With two DIMMs installed, testing was completely stable at 3-3-3-8 2T timings at DDR2-800. Even with further tuning, we were not able to run at 1T command rate at DDR2-800. The highest speed that could run at 1T was DDR2-667. As already stated in the ASUS memory testing, the AM2 does not officially support 2T Command Rate at DDR2-800, so it should come as no surprise that the Epox could not handle the 1T settings. The Gigabyte and ASUS are the only AM2 boards tested thus far that can run at DDR2800 2T, but extensive testing showed no advantage at all in real-world performance using the DDR2-800 1T timings.

Epox MF570SLI DDR2-800 Timings - 4 DIMMs (4/4 slots populated - 2 Dual-Channel Banks)
Clock Speed:	200MHz
Timing Mode:	800MHz - Default
CAS Latency:	3
RAS to CAS Delay:	4
RAS Precharge:	3
RAS Cycle Time:	13
Command Rate:	2T
Voltage:	2.3V

Installing four DIMMs stresses the memory subsystem further. We had to drop the timings slightly to a 4 RAS-to-CAS setting at 2.3V to achieve stable performance with 4 DIMMs. In real-world testing this is practically the same as the fastest 3-3-3 timings we achieved on the fast ASUS M2N32-SLI Deluxe.