Investigations into Athlon X2 Overclocking
by Jarred Walton on December 21, 2005 12:00 PM EST- Posted in
- CPUs
Introduction
Note: This is the second article in a series of overclocking articles. Our first article looked at overclocking a Venice 3200+ chip using two different types of RAM, and it laid the groundwork for what we're doing in this article. We've updated some of our component choices as well as our benchmarks. The major difference is that we're now using an X2 3800+ for the processor, and we also upgraded to a 7800 GTX graphics card. We'll be looking at performance with several types of RAM as well. These articles are not targeted at the advanced overclockers, nor are we going for extreme performance at any cost. The main objective is to use some cost-effective setups and show what sort of performance level can be achieved.
As we mentioned before, there is a risk in overclocking and we do not recommend it for everyone. A system that appears stable for weeks or even months can suddenly have problems, so we definitely wouldn't recommend overclocking for casual computer users who may not be able to recognize or deal with such issues. We take no responsibility for any difficulties or losses that you may experience by using the information in this article, and we certainly take no responsibility for any damage that may occur to any person, place, or object. The risk is yours alone, and a little bit of caution won't hurt. Since we are only using a small subset of parts from the available options, this is merely intended as a baseline performance measurement. Finally, there is no such thing as a "guaranteed result"; you may or may not match the results that we achieve.
We started our recent look at overclocking platforms with the Venice 3000+ and 3200+ processors. Using a $130-$180 processor, we showed that it was possible to come near the performance offered by the extremely fast and extremely expensive FX-57. Actually, we came closer to FX-55 performance, but for about 1/6 the price, that’s still very impressive. Having looked at the Venice core, the next worthwhile upgrade to the processor has to be the move to dual cores. The change also comes with a major increase in price, unfortunately, and depending on the task, it may or may not matter. Current games show no benefit from multiple cores, so unless you plan on running some other CPU intensive tasks in the background while gaming, the upgrade may not be worthwhile.
We’re looking at the Athlon X2 3800+, as you can probably already guess. However, we started work on the benchmarks quite a while back and there are actually a couple of newer options that are potentially higher performing. The new Opteron 165/170 chips use the Denmark core, which is basically the workstation version of the Toledo. While the 165 comes with a lower default clock speed, we would venture to say that it has the potential to overclock just as high as the X2 3800+ that we’ll be using in this article, and likely even higher. (The reasoning stems from the way CPUs are binned and tested. Workstation/server parts undergo much more rigorous validation processes, and typically, this means that the parts have more overclocking headroom. Most server chips are rated extremely conservatively, as component failure is far more undesirable – and uncommon – than in desktop computers.) Combined with the increased L2 cache, you potentially end up increasing performance without spending any more money.
Rather than abandoning all of the benchmarks that we’ve already run, though, we’re going to present the results along with some commentary on the overall experience of overclocking the Manchester core. Also note that retail supplies of the Opteron DC parts may dry up in the near future. So, while we have confidence that the X2 3800+ will be available for purchase six months from now, we can't say the same of the Opteron 165.
Our last article contained a massive amount of introductory material, covering the various components that you need to consider when building a system designed for overclocking. We can safely skip all that this time, though newcomers might find it helpful to review the material. Most of our setup remains unchanged, but let’s explain that in more detail.
Note: This is the second article in a series of overclocking articles. Our first article looked at overclocking a Venice 3200+ chip using two different types of RAM, and it laid the groundwork for what we're doing in this article. We've updated some of our component choices as well as our benchmarks. The major difference is that we're now using an X2 3800+ for the processor, and we also upgraded to a 7800 GTX graphics card. We'll be looking at performance with several types of RAM as well. These articles are not targeted at the advanced overclockers, nor are we going for extreme performance at any cost. The main objective is to use some cost-effective setups and show what sort of performance level can be achieved.
As we mentioned before, there is a risk in overclocking and we do not recommend it for everyone. A system that appears stable for weeks or even months can suddenly have problems, so we definitely wouldn't recommend overclocking for casual computer users who may not be able to recognize or deal with such issues. We take no responsibility for any difficulties or losses that you may experience by using the information in this article, and we certainly take no responsibility for any damage that may occur to any person, place, or object. The risk is yours alone, and a little bit of caution won't hurt. Since we are only using a small subset of parts from the available options, this is merely intended as a baseline performance measurement. Finally, there is no such thing as a "guaranteed result"; you may or may not match the results that we achieve.
We started our recent look at overclocking platforms with the Venice 3000+ and 3200+ processors. Using a $130-$180 processor, we showed that it was possible to come near the performance offered by the extremely fast and extremely expensive FX-57. Actually, we came closer to FX-55 performance, but for about 1/6 the price, that’s still very impressive. Having looked at the Venice core, the next worthwhile upgrade to the processor has to be the move to dual cores. The change also comes with a major increase in price, unfortunately, and depending on the task, it may or may not matter. Current games show no benefit from multiple cores, so unless you plan on running some other CPU intensive tasks in the background while gaming, the upgrade may not be worthwhile.
We’re looking at the Athlon X2 3800+, as you can probably already guess. However, we started work on the benchmarks quite a while back and there are actually a couple of newer options that are potentially higher performing. The new Opteron 165/170 chips use the Denmark core, which is basically the workstation version of the Toledo. While the 165 comes with a lower default clock speed, we would venture to say that it has the potential to overclock just as high as the X2 3800+ that we’ll be using in this article, and likely even higher. (The reasoning stems from the way CPUs are binned and tested. Workstation/server parts undergo much more rigorous validation processes, and typically, this means that the parts have more overclocking headroom. Most server chips are rated extremely conservatively, as component failure is far more undesirable – and uncommon – than in desktop computers.) Combined with the increased L2 cache, you potentially end up increasing performance without spending any more money.
Rather than abandoning all of the benchmarks that we’ve already run, though, we’re going to present the results along with some commentary on the overall experience of overclocking the Manchester core. Also note that retail supplies of the Opteron DC parts may dry up in the near future. So, while we have confidence that the X2 3800+ will be available for purchase six months from now, we can't say the same of the Opteron 165.
Our last article contained a massive amount of introductory material, covering the various components that you need to consider when building a system designed for overclocking. We can safely skip all that this time, though newcomers might find it helpful to review the material. Most of our setup remains unchanged, but let’s explain that in more detail.
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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.