Investigations into Athlon X2 Overclocking
by Jarred Walton on December 21, 2005 12:00 PM EST- Posted in
- CPUs
System Configuration
Since we're only looking at one CPU this time, we added and changed the memory options a bit. Last time, we looked at using value RAM vs. performance RAM based on Samsung TCCD memory. OCZ has moved from the old Rev2 Platinum to their new EL Platinum rated to PC-4800 speeds, and the older Rev2 platinum is no longer being manufactured. We're also adding in some results using OCZ VX Gold, Patriot 2x1GB, and we'll try to run some tests using 4x512MB of the OCZ EL Platinum. The VX RAM will be somewhat limited in performance by the maximum 3.2V that the DFI Infinity provides, but it will also serve as a reference point for tighter timings and lower bandwidth in comparison to the PC-4800 RAM.
Along with the more expensive CPU, we felt that it only made sense to upgrade the graphics card, so we're running with a GeForce 7800 GTX - an XFX model with default 450/1200 clock speeds. Note that for games, the results from the Venice processor will basically match the results that we would achieve with the Manchester, so you can refer to the earlier article to see how this system would perform in games with an X800 Pro. The reverse is also true; if you're only running games without any background tasks, the results here (in games) will show how well the Venice setup should perform with a more expensive graphics card. Here's the complete list of components used.
A complete set of benchmarks for a given configuration requires around 6-8 hours to complete, provided that nothing crashes. Unfortunately, crashes are an all-too-common occurrence when overclocking. A few driver updates (in order to run FEAR optimally) also invalidated earlier results. There are many, many factors that were not fully examined due to time constraints. This is not meant to be a fully comprehensive treatise on overclocking the X2 3800+ or any other processor. Different motherboards are certainly viable - in fact, quite a few motherboards should actually overclock better than the DFI Infinity that was used. This is really intended as a look at performance scaling, as well as some information for those looking to get the best bang for the buck. Building a faster system should be quite easy, but building a system with better performance per dollar (using a dual core processor) will be much more difficult.
I was also contacted by Asetek about testing out their MicroChill and WaterChill cooling solutions. This seemed like an appropriate place to add those to the list of benchmarked configurations, but they really deserve a separate review, so look for that in the very near future. Besides, article bloat and readability can be a problem.
Since we're only looking at one CPU this time, we added and changed the memory options a bit. Last time, we looked at using value RAM vs. performance RAM based on Samsung TCCD memory. OCZ has moved from the old Rev2 Platinum to their new EL Platinum rated to PC-4800 speeds, and the older Rev2 platinum is no longer being manufactured. We're also adding in some results using OCZ VX Gold, Patriot 2x1GB, and we'll try to run some tests using 4x512MB of the OCZ EL Platinum. The VX RAM will be somewhat limited in performance by the maximum 3.2V that the DFI Infinity provides, but it will also serve as a reference point for tighter timings and lower bandwidth in comparison to the PC-4800 RAM.
Along with the more expensive CPU, we felt that it only made sense to upgrade the graphics card, so we're running with a GeForce 7800 GTX - an XFX model with default 450/1200 clock speeds. Note that for games, the results from the Venice processor will basically match the results that we would achieve with the Manchester, so you can refer to the earlier article to see how this system would perform in games with an X800 Pro. The reverse is also true; if you're only running games without any background tasks, the results here (in games) will show how well the Venice setup should perform with a more expensive graphics card. Here's the complete list of components used.
| AMD Overclocking System | |
| Hardware | Component |
| Processor | Athlon 64 X2 3800+ Manchester 2x512K 2.0GHz (OEM) |
| Heat Sink/Fan | Thermalright XP-90 with generic 92mm 3000 RPM fan |
| Motherboard | DFI nF4 INFINITY nForce4 AMD 6.70 drivers |
| Memory | Patriot/PDP 2x1024MB ELL 2-3-2-5-1T OCZ EL Platinum PC4800 2-2-2-5-1T/2.5-4-4-7-1T OCZ Gold VX 2x512MB 2-2-2-8-1T@3.2V Generic PC3200 2x512MB 2.5-3-3-8-1T |
| Video Card | XFX 7800 GTX (450/1250 clocks) ForceWare 81.95 drivers |
| Hard Drive | Seagate SATA 250GB 7200RPM 8MB 7200.8 |
| Optical Drive | NEC 3540A |
| Case | Antec Performance II SX635BII (2x80mm Vantec Stealth fans installed) |
| Power Supply | OCZ PowerStream 600W |
A complete set of benchmarks for a given configuration requires around 6-8 hours to complete, provided that nothing crashes. Unfortunately, crashes are an all-too-common occurrence when overclocking. A few driver updates (in order to run FEAR optimally) also invalidated earlier results. There are many, many factors that were not fully examined due to time constraints. This is not meant to be a fully comprehensive treatise on overclocking the X2 3800+ or any other processor. Different motherboards are certainly viable - in fact, quite a few motherboards should actually overclock better than the DFI Infinity that was used. This is really intended as a look at performance scaling, as well as some information for those looking to get the best bang for the buck. Building a faster system should be quite easy, but building a system with better performance per dollar (using a dual core processor) will be much more difficult.
I was also contacted by Asetek about testing out their MicroChill and WaterChill cooling solutions. This seemed like an appropriate place to add those to the list of benchmarked configurations, but they really deserve a separate review, so look for that in the very near future. Besides, article bloat and readability can be a problem.
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rekabwolrab - Friday, February 24, 2006 - link
I'm new to OC and both the articles were very nice. Good Job. I am looking forward to the next installment with HSF/Cooling.shoeish - Friday, February 24, 2006 - link
Any results to share about watercooling or stock HSF with this chip yet?mcpdigital - Wednesday, December 28, 2005 - link
This article comes in the right moment since lots of people are thinking about upgrading their PCs or just did it.In my case I have a pretty simmilar configuration with LanParty Ultra-D, 3800 X2 and OCZ EL 3200 (2x1GB).
I found the breakeven of my setup at 280x9(2520), Mem at 210 MHz CAS 2,3,3,5 1T and HT x 3. Memory is running at its best, with 1T, Fastest in BIOS and CAS2 achieving around 61000 MB/s transfer rate running Sandra 2005 Pro, a value that is a bit under the maximum bandwidth with HT @1680 MHz of 6720MB/s
Anything over this speed makes the system unstable and requires a lot of slowdowns in other settings, voltage and temps raising fast, its a bad tradeoff IMO.
So Anandtech simple of the 3800 X2 seems a little better than mine, not that I'm not happy, I'm for sure.
Marcelo
Some1ne - Sunday, December 25, 2005 - link
Re: If you have any specific requests or suggestions before then, let me know.I noticed that as you increased the clock speed, you also increased your chipset voltage in a fairly linear way. I question whether or not this is really necessary or beneficial. I have a MSI Neo4 Platinum mainboard, and I've never had to touch the chipset voltage when overclocking. In fact, some of the behavior I observed when playing with it seemed to imply that the chipset got slightly less stable with higher voltages (though I didn't do enough testing to know conclusively if the relationship holds or not). Using the stock chipset voltage, I was able to hit:
2464 MHz (352x7) on a Winchester 3000+ w/ 6.6% over-VID on the CPU
2420 MHz (242x10) on a Manchester 3800+ w/ 10% over-VID on the CPU
2400 MHz (400x6) on a Winchester 3000+ w/ 6.6% over-VID on the CPU, just to see if the board would run stably at a 400 MHz "fsb" setting...it did
So as far as I can tell, boosting the chipset voltage is not necessary in order to attain a good overclock. It might be interesting if you could do tests to see what, if any, impact it has on stability at higher clock speeds, or maybe at least re-run your 2.7 GHz tests with stock chipset voltage just to make sure that your instability wasn't coming from an overheating chipset.
JarredWalton - Monday, December 26, 2005 - link
The results reported are only after testing all of the lower voltages. I encountered instability without the increased voltage to the chipset and processor. That said, other motherboards may not behave the same. I intend to switch to a different motherboard for the cooling tests -- a DFI LanParty SLI-DR. I will be sure to comment on whether the voltage requirements change or not.AtaStrumf - Friday, December 23, 2005 - link
Just want to commend you for a really thorough article. I miss that from other AT editors as of late.I also agree that all that ultra high end memory with tight timings is an absolute overkill for all but the most rabid overclockers. This is especially true since Athlon got an on die memory controller and became Athlon64. Just get some good quality RAM that will get you to 220-233 MHz so you have some headroom with BIOS FSB/dividers settings, because generic usually craps out at 201-203 MHz (sad but true).
Visual - Thursday, December 22, 2005 - link
Fantastic article, folks!It really showed alot. Sure, as someone commented, using a better mobo might have been interesting... but after all its the CPU that is important here, and you made the differences in performace with varying oc well presented.
I have to say, this article showed a surprisingly high difference between memory types too. You did comment in the end that there wasn't much difference, but there are some cases where there is :) 3dMark05 is the extreme case i guess, and not "real world" enough to be worth the added price, but 15fps or more in a lot of games from going from generic to the PC4800 mem isn't bad too. Seriously, this article showed the importance of memory way clearer than any of your RAM roundups in the past.
What is still dissapointing is that the test didn't reach the near-3ghz ocs a lot of people are bragging with on some forums :p But this is a good thing in a way, as now there won't be any misled readers buying the chip and expecting unrealistic achievments. I'm still curious about what the chips can do at max though, so I'm looking forward to your stock/Chill tests :) Maybe comparison with both infinity and lanparty boards? Maybe trying out several chips so you can give us a somewhat more realistic max average oc? (Hehe, no, scratch that last one. I don't want AT going broke from buying out all the X2s, plus no matter how many chips you test, the readers' own luck will deviate from yours)
Visual - Thursday, December 22, 2005 - link
Oh hey, I want to add a bit but there is no edit feature. So here goes...The RAM difference is much higher than with the singlecore veince. This does match with the assumption that two cores would need (and benefit) more bandwidth. So it also brings hope that the move to AM2 and DDR2 will have an even further boost, atleast for the dualcores. I'm already drooling over an imaginary AM2 X2 oced with DDR2 800mhz ram or faster :p
JarredWalton - Thursday, December 22, 2005 - link
I would say the performance difference shown here (relative to Venice) is from two things. First, two cores can use more bandwidth, though most of these tests won't show that since they're single-threaded. Second, the faster graphics card allows the CPU to really stretch its legs.Once you're at realistic settings for this system (minimum 1280x1024 resolution), the scores get a lot closer. Also, 3DMark has a pretty large deviation between runs - probably 3% or so. I didn't run 3DMark multiple times looking for the best score, so the results may not present a completely accurate representation of performance. Still, the CPU tests do show generic RAM at a pretty major disadvantage as clock speed increases. If 3DMark05's CPU test is an accurate estimate of multithreaded game performance, we're looking at a 25% difference! But I wouldn't put too much stock in 3DMark05. :p
Visual - Friday, December 23, 2005 - link
From what I read on the futuremark forums once, even though 3dmark05 is multithreaded, vertex processing in cpu tests is singlethreaded (some dx9 functionality from MS, not developed by futuremark) so isnt taking full advantage of dualcores still.