Socket 754 Roundup, Part 3: Asus, Soltek & DFI

Asus K8N-E: Overclocking and Stress Testing

FSB Overclocking Results

Front Side Bus Overclocking Testbed
Default Voltage
Processor:	Athlon 64 3200+ 2.0GHz
CPU Voltage:	1.5V (default)
Cooling:	Thermaltake Silent Boost K8 Heatsink/Fan
Power Supply:	OCZ Power Stream 520W
Memory:	OCZ PC3200 EL Platinum Rev. 2 or Geil PC3200 Ultra X
Maximum OC: (Standard Ratio)	246 x 10 (IDE), 230 x 10 (SATA) 2460MHz (+23%)
Maximum FSB: (Lower Ratio)	271 x 9 (1:1 Memory, IDE, 2 DIMMs) 230 x 9 at (1:1 Memory, SATA, 2 DIMMs)

The decision by Asus to use Silicon Image SATA instead is really a drawback in overclocking. Whether using the 2 nVidia SATA channels or any of the 4 Sil3114 channels, the highest overclock that we could achieve with our standard SATA drive was 230, much lower than some other nF3-250 boards. When using an IDE drive, the K8N-E fared better, reaching a stable 271 FSB at 1:1 before failing boot. While this is a much better overclock, it is still below the performances of the DFI, MSI, Epox, and Chaintech 754 boards that we have tested.

Due to the overclock limits found with SATA drives on the Asus, we would recommend using IDE drives with the Asus if you plan to overclock. The Asus can handle reasonable overclocks with a SATA drive, and we confirmed AGP/PCI is definitely working. However, the highest overclocks could only be achieved using IDE hard drives.

Memory Stress Test Results:

The memory stress test is very basic, as it tests the ability of the Asus K8N-E to operate at its officially supported memory frequency (400MHz DDR), at the best performing memory timings that our OCZ PC3200 Platinum Rev. 2 modules will support. Memory stress testing was conducted by running RAM at 400MHz with 2 DIMM slots filled. However, please keep in mind that Socket 754 is single-channel and will still operate at top speed with just one DIMM.

Stable DDR400 Timings - 2 DIMMs (2/3 Dimms populated - Single-Channel mode)
Clock Speed:	200MHz
CAS Latency:	2.0
RAS to CAS Delay:	2T
RAS Precharge:	10T*
Precharge Delay:	2T
Command Rate:	1T

*Several memory tests have shown that memory performs fastest on the nVidia nForce chipsets at a TRas (RAS Precharge) settings in the 9 to 13 range. We ran our own Memory Bandwidth tests with memtest86 with TRas settings from 5 to 15 at a wide range of different memory speeds. The best bandwidth was consistently at 9 to 11 at every speed, with TRas 10 always in the best range at every speed. The performance improvement at TRas 10 was only 2% to 4% over TRas 5 and 6 depending on the speed, but the performance advantage was consistent across all tests. All benchmarks were run at a TRas setting of 10.

The Asus K8N-E was completely stable with 2 DIMMs at the best performing settings of 2-2-2-10, at default speed. Command Rate was set to Auto, but is reported as performing at 1T in SiSoft Sandra benchmarks.

Filling all three available memory slots is more strenuous on the memory sub-system than testing 2 DIMMs on a motherboard.

Stable DDR400 Timings - 3 DIMMs (3/3 DIMMs populated - Single-Channel mode)
Clock Speed:	200MHz
CAS Latency:	2.0
RAS to CAS Delay:	2T
RAS Precharge:	10T*
Precharge Delay:	2T
Command Rate:	2T

*Several memory tests have shown that memory performs fastest on the nVidia nForce chipsets at a TRas (RAS Precharge) settings in the 9 to 13 range. We ran our own Memory Bandwidth tests with memtest86 with TRas settings from 5 to 15 at a wide range of different memory speeds. The best bandwidth was consistently at 9 to 11 at every speed, with TRas 10 always in the best range at every speed. The performance improvement at TRas 10 was only 2% to 4% over TRas 5 and 6 depending on the speed, but the performance advantage was consistent across all tests. All benchmarks were run at a TRas setting of 10.

We were very pleased to find that 3 DS DIMMs (1.5GB) of memory worked fine at the same aggressive timings that we used for 2 DIMMs. This is very good performance for the K8N-E in our memory stress test. However, we should point out that while the Asus was stable in most of our benchmark tests with 3 DIMMs, it was not completely stable in Quake 3 or Return to Castle Wolfenstein with 3 DIMMs. Memory voltage increases were just not an option. It appears that our fast memory really wants 2.8V with 3 DIMMs and this shows up in some games. The limited memory voltage range may well be your real limiter in overclocking with 3 DIMMs.