Asus A8R-MVP: Mainstream Rocket
by Wesley Fink on November 23, 2005 1:15 AM EST- Posted in
- Motherboards
Overclocking
Screen captures on the first page have already announced that the Asus A8R-MVP has set new overclocking records in our testing. We actually found 330 to be stable in memtest86 and booted into Windows at a little more than 330 with memory set to a DDR400 starting point. However, Windows was not completely stable at 330 and required a slight lowering to 325 (DDR650). The 325 setting was completely stable, ran our benchmarks, and ran for more than 2 days on just air cooling.
Our first efforts at overclocking the A8R-MVP ran into a road block at just over 260. We have found some Asus boards in the past that did not like overclocks to be immediately set to high values, so we started again at 250. By going up just 5 to 10FSB at a time, we were able to reach 325. Since we had no idea that we would reach such a high OC on this mainstream board, we have screen captures at every 5MHz from about 270 to 330. Our advice to overclockers on this board is to move the overclock up slowly.
*UPDATE: After further testing we have concluded that the A8R-MVP handles 1T timings only to about 260-265. Above 260-265 you will need 2T timings to reach 325 or so clock frequency. We ran into a wall at 260 and apparently the BIOS reset. The default is 2T and we didn't catch the Command Rate reset. This board uses very aggressive timings, and the 2T memory bandwidth was so fast we did not realize the board was actually running at 2T. This does not change the fact that 325 at 2T is an outstanding overclock, but it is achieved at 2T timings, and not at 1T as originally reported.
Those who don't understand overclocking or who don't want to bother will find extensive automatic overclocking options in the Asus BIOS. This allows you to set an overclock and have the board adjust the related settings. These work well for modest overclocking, but they will not allow the extreme results achieved manually on the Asus A8R-MVP.
Memory Stress Testing
The Asus A8R-MVP easily handles 2-2-2-7-1T timings at stock speed, as do almost any of the current boards for AMD Socket 939 from NVIDIA, SiS, VIA, ATI, and ULi. However, the default setting for Command Rate in the Asus BIOS is 2T, and you need to manually set Command Rate to 1T for best performance with 2 DIMMs in Dual Channel mode. Asus tells us that this was done to accommodate some memory manufacturers that had asked for a default 2T Command Rate for maximum compatibility with their memory. Once set, we had no issues using 1T command Rate with any memory that we tested.
Running four double-sided 512MB or 1GB DIMMs is much more demanding than running two DS DIMMs, and Asus did not have any extra magic here. Like every board that we have tested except the DFI RDX200, we needed to drop the Command Rate to 2T with 4 DS DIMMs. With 4 DIMMs, the A8R-MVP remained stable with the same aggressive 2-2-2-7 timings used for two DS DIMMs.
*7T was determined by MemTest86 benchmarks to deliver the widest bandwidth with the ATI Rx480/482 chipset. While the board would operate at tRAS of 5T or lower, all benchmarks were run at 7T.
| Asus A8R-MVP Overclocking Testbed | |
| Processor: | Athlon 64 4000+ (2.4GHz, 1MB Cache) |
| CPU Voltage: | 1.45V (default 1.40V) |
| Cooling: | Thermaltake Silent Boost K8 Heatsink/Fan |
| Power Supply: | OCZ Power Stream 520W |
| Memory: | OCZ PC3200* Platinum Rev. 2 (Samsung TCCD Memory Chips) *The current equivalent OCZ memory is OCZ PC4800 |
| Hard Drive: | Seagate 120GB 7200RPM SATA 8MB Cache |
| Maximum OC: (Standard Ratio) |
246x12 (4x HT, 2.5-3-3-7) 2952MHz (+23%) |
| Maximum FSB: (Lower Ratio) |
325 x 9 (3x HT, 2T*, 3-4-3-8) (2925MHz, 2 DIMMs in DC mode) (+62.5% Bus Overclock) |
Screen captures on the first page have already announced that the Asus A8R-MVP has set new overclocking records in our testing. We actually found 330 to be stable in memtest86 and booted into Windows at a little more than 330 with memory set to a DDR400 starting point. However, Windows was not completely stable at 330 and required a slight lowering to 325 (DDR650). The 325 setting was completely stable, ran our benchmarks, and ran for more than 2 days on just air cooling.
Our first efforts at overclocking the A8R-MVP ran into a road block at just over 260. We have found some Asus boards in the past that did not like overclocks to be immediately set to high values, so we started again at 250. By going up just 5 to 10FSB at a time, we were able to reach 325. Since we had no idea that we would reach such a high OC on this mainstream board, we have screen captures at every 5MHz from about 270 to 330. Our advice to overclockers on this board is to move the overclock up slowly.
*UPDATE: After further testing we have concluded that the A8R-MVP handles 1T timings only to about 260-265. Above 260-265 you will need 2T timings to reach 325 or so clock frequency. We ran into a wall at 260 and apparently the BIOS reset. The default is 2T and we didn't catch the Command Rate reset. This board uses very aggressive timings, and the 2T memory bandwidth was so fast we did not realize the board was actually running at 2T. This does not change the fact that 325 at 2T is an outstanding overclock, but it is achieved at 2T timings, and not at 1T as originally reported.
Those who don't understand overclocking or who don't want to bother will find extensive automatic overclocking options in the Asus BIOS. This allows you to set an overclock and have the board adjust the related settings. These work well for modest overclocking, but they will not allow the extreme results achieved manually on the Asus A8R-MVP.
Memory Stress Testing
The Asus A8R-MVP easily handles 2-2-2-7-1T timings at stock speed, as do almost any of the current boards for AMD Socket 939 from NVIDIA, SiS, VIA, ATI, and ULi. However, the default setting for Command Rate in the Asus BIOS is 2T, and you need to manually set Command Rate to 1T for best performance with 2 DIMMs in Dual Channel mode. Asus tells us that this was done to accommodate some memory manufacturers that had asked for a default 2T Command Rate for maximum compatibility with their memory. Once set, we had no issues using 1T command Rate with any memory that we tested.
Running four double-sided 512MB or 1GB DIMMs is much more demanding than running two DS DIMMs, and Asus did not have any extra magic here. Like every board that we have tested except the DFI RDX200, we needed to drop the Command Rate to 2T with 4 DS DIMMs. With 4 DIMMs, the A8R-MVP remained stable with the same aggressive 2-2-2-7 timings used for two DS DIMMs.
| Stable DDR400 Timings - 4 DIMMs (4/4 DIMMs populated) |
|
| Clock Speed: | 200MHz |
| CAS Latency: | 2.0 |
| RAS to CAS Delay: | 2T |
| RAS Precharge: | 7T* |
| Precharge Delay: | 2T |
| Command Rate: | 2T |
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74 Comments
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AllanLim - Sunday, December 11, 2005 - link
What I should have said is that the BIOS memory option maxes out at 200, so why is there a need to raise memory timings to 3-4-3-8 when at 325x9.Wesley Fink - Sunday, December 11, 2005 - link
200 is the starting point (400DDR) in BIOS, and memory clock floats with the CPU frequency. Thus at 325 Clock Speed the memory set at 200 is running DDR650. Memory floats with clock frequency on almost every board we test.If you start memory at 166 (333), it would run at about 270 (DDR540) with the Clock Frequency set to 325. You may want to do some reading or ask some questions in our Forums to better understand how this works.
AllanLim - Sunday, December 11, 2005 - link
Got it, checked out Zebo's article in forums, my bad for not checking this out earlier. Thus begins my foray into AMD64 overclocking.Many thnx for help.
EnlightenedOne - Monday, December 12, 2005 - link
K great. Thanks for the quick reply wes :DFinal question I promise, lol.
At the 325 x 9 setting, how stable do you think the CPU would be @ load? For example, I'm going to be playing alot of BF2 and Quake 4 with this new set up. I was wondering if it will be atleast 6 hours stable in those games at load.
What do you think?
EnlightenedOne - Monday, December 12, 2005 - link
I'm also trying to see if I can tighten those dram timings a bit by adding more voltage. What are the tighest/stable that you got with a higher ram voltage?EnlightenedOne - Thursday, December 8, 2005 - link
Hey Wesley, Great Review!I was wondering a few things with this motherboard and the setup.
First, do you think the clawhammer 4000+ would overclock better than the Diego?
What voltage are you feeding your ram to reach such a high frequency?
Do you suggest using the 246 x 12 or the 325 x 9 set up for games?
Finally, what voltage are you feeding the PCIe slot? Also, why haven't you upped the voltage to your cpu core to maintain stability and go beyond 2 days? :)
Wesley Fink - Friday, December 9, 2005 - link
Our San Diego clocks almost exactly the same as the Clawhammer 4000+, but it runs cooler. I would choose San Diego. We tested both on this board, as we have done for the last few reviews, found performance very similar (we had a fantastic Clawhammer that may not have been typical), and moved to the 90nm CPU for future reviews.The OCZ TCCD RAM was only getting 2.75V-2.8V. My pairs really don't like or need more voltage to reach high overclocks.
Which you use depends on your RAM. In most cases you can get tighter timings at 246 than at 325. The best speed is a balance of highest RAM clock consistent with tightest timings. There is no cut-and-dried answer to your question.
I did not overclock PCIe, but the chipset and/or PCIe sometimes reauires a small voltage boost at extreme overclocks.
If you check the OC page I am using 1.45V vCore which is a modest OC of .05V from the default 1.4V. It didn't reboot after 2 days, we had to move on to other reviews. It might still be running fine at 325x9 for all we know.
EnlightenedOne - Sunday, December 11, 2005 - link
Awesome. 1 Quick last simple question. Did you slowly up the FSB through the bios and reboot, then up it again? Or did you use a windows based overclocker program that asus provided? If using the reboot method.. how long did you let it run before rebooting and upping the fsb a little more. If windows method, how long did you wait before upping the FSB little by little? Thanks :DWesley Fink - Sunday, December 11, 2005 - link
I rebooted and upped the frequency a bit, went into windows, then rebooted and upped frequency again.abakshi - Wednesday, December 7, 2005 - link
Hmm...this is looking pretty good. But GigE performance is pretty important for me -- if I get a separate PCI-E 1x GigE card, can I match the throughput of the integrated PCI-E chipsets, like the Marvel, etc.?Any recommendations for a card? From a quick look around, I've seen an expensive D-Link ($80), some assorted others (SysKonnect, etc.) at varying ranges. Any benches of these for reference?
And if I put in two X1800XT's, I wouldn't be able to fit a 1x card in between, right? What about with single-slot cards like the X1800XL?