Asus P4S800D-E Deluxe & Gigabyte 8S655TX Ultra: SiS 655TX Challenges Intel's Best

Gigabyte 8S655TX Ultra: Stress Testing

We performed stress tests on the 8S655TX Ultra in these areas and configurations:

1. Chipset and motherboard stress testing, conducted by running the FSB at 242MHz with synchronous (1:1) memory speed (DDR484) with OCZ 4200 EL memory.
2. Memory stress testing, conducted by running RAM at 400MHz with 2 Dual-Channel (1 bank) DIMM slots filled and at 400MHz with all 4 Dual-Channel (2 bank) DIMM slots filled at the lowest memory timings possible with Mushkin PC3500 Level II memory.

Front Side Bus Stress Test Results:

We ran a full range of stress tests and benchmarks to ensure the 8S655TX was absolutely stable at the overclocked FSB speed. This included Prime95 torture tests, and the addition of other tasks — data compression, various DX8 and DX9 games, and apps like Word and Excel — while Prime95 was running in the background. At default voltage, 242MHz was the highest overclock that we were able to achieve with a synchronous memory setting.

Memory Stress Test Results:

This memory stress test is very basic, as it simply tests the ability of the 8S655TX Ultra to operate at its officially supported memory frequency (400MHz DDR), at the lowest supported memory timings that our Mushkin High Performance ECC Registered Modules will support:

Stable DDR400 Timings — 2 DIMMs 2/4 DIMMs populated — 1 DC bank
Clock Speed:	200MHz
Timing Mode:	128-bit DC
CAS Latency:	2.0
Bank Interleave:	N/A
RAS to CAS Delay:	2T
RAS Precharge:	6T
Precharge Delay:	2T
Command Rate:	Auto

We had no problem running 2 DS 512MB DIMMs of our standard Mushkin PC3500 Level2 or 2 DS 512MB OCZ 3500 Platinum Ltd in the 8S655TX Ultra at the most aggressive timings. We did achieve complete stability at 2-2-2-6 timings at the default voltage setting. However, our past experience with Gigabyte SiS designs would suggest that the 8S655TX may actually be running closer to 2.6V at “normal” settings. We are pleased that default voltage was fine for 2-2-2-6 timings, but you should not make too much of this finding.

Filling all available memory banks is more strenuous on the memory subsystem than testing 2 DIMMs, but we had no problem at all running with all 4 DIMMs filled providing 2 Dual-Channel Banks.

Stable DDR400 Timings — 4 DIMMs 4/4 DIMMs populated — 2 DC bank
Clock Speed:	200MHz
Timing Mode:	128-bit DC
CAS Latency:	2.0
Bank Interleave:	N/A
RAS to CAS Delay:	2T
RAS Precharge:	6T
Precharge Delay:	2T
Command Rate:	Auto

The required memory timings with 4 DIMMs were the same as 2 DIMMs, the fastest 2-2-2-6 timings our memory could achieve. The 4-DIMM setup worked fine at “normal” memory voltage, the same as our 2 DIMM setup. The 8S655TX Ultra was completely stable at these timings and voltage.