Soltek SL-PT880Pro-FGR: VIA Dual-Channel for the Pentium 4

Overclocking and Stress Testing: Soltek SL-PT880Pro-FGR

FSB Overclocking Results

The Soltek PT880Pro has all the ingredients for top-notch overclocking, so we were anxious to see what the board could do. With Intel chipsets and some boards with SiS655TX reaching incredible overclocks with P4 chips, we were expecting the same from the PT880 chipset.

Front Side Bus Overclocking Testbed
Default Voltage		Maximum Overclock
Processor:	2.4C Pentium 4 2.4GHz	2.4C Pentium 4 2.4GHz
CPU Voltage:	1.525V (default)	1.6V (Maximum vCore)
Cooling:	OCZ Eliminator 2	OCZ Eliminator 2
Power Supply:	Antec TruePower 430W	Antec TruePower 430W
Maximum OC:	2616MHz (+9%) 218FSB	2654MHz (+10.5%) 221FSB

Our overclocking chart needs a little bit of explanation. We first tested with a 3.2C that is known to do 3.7GHz (233x160 at default voltage). Our overclocks were a disappointing 218-220 and we needed a little extra voltage just to make it to 220. At first, we thought that the new VIA PCI/AGP lock was not working. Soltek checked operation of the asynchronous bus in their lab with an oscilloscope and found it to be working. We then checked it ourselves with PC Geiger, which also showed the PCI bus remaining fixed at 33.3MHz.

At that point, we swapped to our 2.4C that is used to test memory. You have seen this chip at 280-291 in memory testing, and we have had it over 300 in 5:4 testing. With this 2.4C, we were confident that we were completely eliminating the CPU and voltage as an overclocking issue. To our surprise, the 2.4C also topped out in the 218-222 range.

We can only conclude that VIA and/or Soltek have work to do on the overclocking capabilities of the PT880. With both the Intel and SiS chipsets reaching very high overclocks with the current Pentium 4 chips, the overclocking performance of the PT880 is a complete disappointment in comparison. Since we have found in the past that Soltek knows how to produce great overclocking boards, we suspect the issue lies with the PT880 chipset. It now appears that Soltek's decision to provide a CPU adjustment range only to 250 was not an oversight. Based on these results, 250 is an ambitious overclocking goal on this chipset and board.

Front Side Bus Stress Test Results:

As part of normal overclocking tests, a full range of stress tests and benchmarks were run to ensure the PT880Pro was stable at each 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. Finally, we ran our benchmark suite, which includes Veritest Winstone 2004 suite, Unreal Tournament 2003, SPECviewperf 7.1, and Aquamark 3. 218MHz was the highest overclock that we were able to achieve with the Soltek while running these tests at default voltage.

Memory Stress Test Results:

The memory stress test is very basic, as it simply tests the ability of the PT880Pro to operate at its officially supported memory frequency (400MHz DDR) at the lowest supported memory timings that our Mushkin PC3500 Level 2 or OCZ PC3500 Platinum Ltd Modules will support. Memory stress testing was conducted by running RAM at 400MHz with 2 DIMM slots filled.

Stable DDR400 Timings - 2 DIMMs (2/4 DIMMs populated - DC mode)
Clock Speed:	200MHz
Timing Mode:	N/A
CAS Latency:	2.0
Bank Interleave:	4
RAS to CAS Delay:	3T
RAS Precharge:	6T
Precharge Delay:	2T
Command Rate:	2T

The PT880Pro was not completely stable with either the most aggressive 2-2-2-6 timings or 1T command rate. However, by slightly relaxing Ras-to-Cas to 3T and setting a 2T command rate, we were able to achieve complete stability. We had no problem running 2 DS 512MB DIMMs of our standard Mushkin PC3500 Level2 or OCZ PC3500 Platinum Ltd in the Soltek at these timings. Both of these memories were completely stable at the default memory voltage of 2.5V.

Filling all four available memory slots in a 2-bank dual-channel configuration is more strenuous on the memory subsystem than testing 2 DIMMs as a single DC bank. We were very pleased to find 4 DS DIMMs (2GB) of memory worked fine at the same timings we used for 2 DIMMs. Recent VIA chipsets have had some problems with all DIMM slots filled, but the PT880 seems to have solved that issue. Performance with all 4 DIMMs installed was very stable.

Stable DDR400 Timings - - 4 DIMMs (4/4 DIMMs populated - 2 DC mode)
Clock Speed:	200MHz
Timing Mode:	N/A
CAS Latency:	2.0
Bank Interleave:	4
RAS to CAS Delay:	3T
RAS Precharge:	6T
Precharge Delay:	2T
Command Rate:	2T

We tested the memory timings with 2 DC banks (4 DS DIMMs) using several stress tests and general applications to guarantee stability. Prime95 torture tests were successfully run at the timings listed in the above charts. We also ran Sciencemark (memory tests only) and Super Pi. None of the stress tests created any stability problems for the Soltek PT880Pro at these memory timings. VIA has produced a very capable memory controller in the PT880 chipset.