Investigations into Socket 939 Athlon 64 Overclocking
by Jarred Walton on October 3, 2005 4:35 PM EST- Posted in
- CPUs
Closing Thoughts
This has been a huge undertaking, and we hope that you enjoy the results and overclocking information. Many guides of various forms already exist on the internet, but we really wanted to take a look at some of the options offered by the Venice core processors as well as trying to get by with value RAM instead of higher cost alternatives. After all, why save $60 on the CPU only to spend the same amount of money upgrading the RAM? So, other than a look at how to overclock, what have we learned?
The biggest deal for many people will be the results using standard PC-3200 RAM and higher memory dividers. While you won't be able to match the performance of a system that uses better quality RAM, the largest margin of victory was still under 10% (not counting instances where 2T command rates were used). The average was closer to 5%, and realistically, you won't notice a 5% performance loss. Outside of games, the performance losses attributed to value RAM are even less, with video encoding only losing a few percentages in speed. What it really comes down to is cost. We used a $190 CPU with $85 and $150 RAM. Going with a 3000+ and the value RAM saves almost $125 and should get you about 90 to 95% of the performance of the more expensive setup. That $125 could then be put towards a faster GPU, which will have a far greater impact on games than a 200 or even 400 MHz CPU upgrade.
Other than the value vs. quality RAM debate, what about the overall experience of overclocking this configuration? We were pretty impressed with the "budget" DFI motherboard. While I haven't personally used the Ultra-D, there were few problems on the Infinity that I couldn't deal with. Even with a good motherboard, though, overclocking can be exasperating at times. With value RAM rated at DDR400 2.5-3-3-8, it was at times difficult to get those timings even at speeds slightly below the rated DDR400, particularly on the high end of the overclocking scale. While I'd be willing to run 2.6 or even 2.7 GHz with the OCZ RAM, I have a feeling that long-term stability with the value RAM might require dropping to 2.5 to 2.6 GHz instead, or else increasing the timings to 3-3-3-8 or even 3-4-4-8. And speaking of timings, the 2T command rate should almost always be avoided. Results for a couple of settings were included, and overall, you would be better off running 100 or even 200 MHz slower with 1T command rate.
Something else that all of the graphs and results don't indicate is some of the oddities that can come up with overclocking. The SATA drive would sometimes make strange noises during the Windows XP boot sequence, almost like the HDD heads were seeking back and forth across the drive. Everything seems to indicate that the overclock is somehow to blame, and while a BIOS update might be able to address this particular issue, the end result is that XP would sometimes take up to 5 minutes to load at higher overclocks. Once loaded, everything worked fine, and the HDD was still running at full SATA spec. Another possible cause for delays in loading XP could be the networking subsystem. The testbed was connected to a gigabit switch, and we've experienced issues with network stability on overclocked PCs in the past. An MSI K8N Neo Platinum, for example, drops network connectivity after a day or two in many - but not all - overclocked configurations. We didn't experience this particular problem during testing of the DFI board, but it's something to look for on your own systems. Dropping the speed of the HyperTransport bus also helped avoid some - but not all - of the hard drive access delays. As we said, be prepared for some strange behavior now and then during overclocking.
The final comment that we want to make is about the long term viability of overclocking. We started this article with a warning, and we'll end it the same way. While we haven't encountered problems with the CPU yet, that doesn't mean that the chip won't simply die in a few weeks, months, or hopefully, not for years. Higher voltages in particular can affect CPU life, as they can accelerate electron drift. As we couldn't get to 2.7 GHz without running at 1.750V, we're a little hesitant to recommend that speed as a long-term solution. Given that 2.6 GHz is, at worst, only 4% slower, we'd recommend that as a better solution and go with the 1.650V setting. That's similar to how Intel supposedly binned CPUs back in the socket 7 days: they would reportedly increase CPU clock speeds until the chips failed, and then sell them two bins below the maximum stable clock speed. Whether that's rumor or in truth how they operate (operated?), running at speeds slightly slower than your "stable" maximum will be preferred by many. Crashing even every couple of days or once a week is too reminiscent of the Windows 95 era.
We've tried to get across the point that there are no guarantees with overclocking. Even with that disclaimer, we're pretty confident that the vast majority of Athlon 64 Venice chips will run at 2.4 GHz, and probably even 2.6 GHz. It may require higher voltages, better cooling, or relaxed memory timings, but with the right combination of parts, it's a relatively safe bet. Worst case scenario, try running at 3-4-4-9-2T memory timings, then try running at those timings and PC2700 or even PC2100 on the RAM. If it's still unstable, it might be your motherboard or some other factor holding you back. Even a 15% overclock is still pretty good, though, and you can probably get that without any special equipment other than an enthusiast motherboard.
That closes up this overclocking article. We have several similar articles planned, though we're interested in feedback from the readers. Was this too superficial? Do you want more details on tweaking memory timings beyond what we've mentioned? Or is the mix of benchmarks, settings, and results about right? Let us know. This article was long, with a large portion dedicated to introducing the uninitiated to the art and practice of overclocking. Future articles in this series will focus more on the end results and refer back to the concepts presented here. As always, any recommendations and comments are welcome.
This has been a huge undertaking, and we hope that you enjoy the results and overclocking information. Many guides of various forms already exist on the internet, but we really wanted to take a look at some of the options offered by the Venice core processors as well as trying to get by with value RAM instead of higher cost alternatives. After all, why save $60 on the CPU only to spend the same amount of money upgrading the RAM? So, other than a look at how to overclock, what have we learned?
The biggest deal for many people will be the results using standard PC-3200 RAM and higher memory dividers. While you won't be able to match the performance of a system that uses better quality RAM, the largest margin of victory was still under 10% (not counting instances where 2T command rates were used). The average was closer to 5%, and realistically, you won't notice a 5% performance loss. Outside of games, the performance losses attributed to value RAM are even less, with video encoding only losing a few percentages in speed. What it really comes down to is cost. We used a $190 CPU with $85 and $150 RAM. Going with a 3000+ and the value RAM saves almost $125 and should get you about 90 to 95% of the performance of the more expensive setup. That $125 could then be put towards a faster GPU, which will have a far greater impact on games than a 200 or even 400 MHz CPU upgrade.
Other than the value vs. quality RAM debate, what about the overall experience of overclocking this configuration? We were pretty impressed with the "budget" DFI motherboard. While I haven't personally used the Ultra-D, there were few problems on the Infinity that I couldn't deal with. Even with a good motherboard, though, overclocking can be exasperating at times. With value RAM rated at DDR400 2.5-3-3-8, it was at times difficult to get those timings even at speeds slightly below the rated DDR400, particularly on the high end of the overclocking scale. While I'd be willing to run 2.6 or even 2.7 GHz with the OCZ RAM, I have a feeling that long-term stability with the value RAM might require dropping to 2.5 to 2.6 GHz instead, or else increasing the timings to 3-3-3-8 or even 3-4-4-8. And speaking of timings, the 2T command rate should almost always be avoided. Results for a couple of settings were included, and overall, you would be better off running 100 or even 200 MHz slower with 1T command rate.
Something else that all of the graphs and results don't indicate is some of the oddities that can come up with overclocking. The SATA drive would sometimes make strange noises during the Windows XP boot sequence, almost like the HDD heads were seeking back and forth across the drive. Everything seems to indicate that the overclock is somehow to blame, and while a BIOS update might be able to address this particular issue, the end result is that XP would sometimes take up to 5 minutes to load at higher overclocks. Once loaded, everything worked fine, and the HDD was still running at full SATA spec. Another possible cause for delays in loading XP could be the networking subsystem. The testbed was connected to a gigabit switch, and we've experienced issues with network stability on overclocked PCs in the past. An MSI K8N Neo Platinum, for example, drops network connectivity after a day or two in many - but not all - overclocked configurations. We didn't experience this particular problem during testing of the DFI board, but it's something to look for on your own systems. Dropping the speed of the HyperTransport bus also helped avoid some - but not all - of the hard drive access delays. As we said, be prepared for some strange behavior now and then during overclocking.
The final comment that we want to make is about the long term viability of overclocking. We started this article with a warning, and we'll end it the same way. While we haven't encountered problems with the CPU yet, that doesn't mean that the chip won't simply die in a few weeks, months, or hopefully, not for years. Higher voltages in particular can affect CPU life, as they can accelerate electron drift. As we couldn't get to 2.7 GHz without running at 1.750V, we're a little hesitant to recommend that speed as a long-term solution. Given that 2.6 GHz is, at worst, only 4% slower, we'd recommend that as a better solution and go with the 1.650V setting. That's similar to how Intel supposedly binned CPUs back in the socket 7 days: they would reportedly increase CPU clock speeds until the chips failed, and then sell them two bins below the maximum stable clock speed. Whether that's rumor or in truth how they operate (operated?), running at speeds slightly slower than your "stable" maximum will be preferred by many. Crashing even every couple of days or once a week is too reminiscent of the Windows 95 era.
We've tried to get across the point that there are no guarantees with overclocking. Even with that disclaimer, we're pretty confident that the vast majority of Athlon 64 Venice chips will run at 2.4 GHz, and probably even 2.6 GHz. It may require higher voltages, better cooling, or relaxed memory timings, but with the right combination of parts, it's a relatively safe bet. Worst case scenario, try running at 3-4-4-9-2T memory timings, then try running at those timings and PC2700 or even PC2100 on the RAM. If it's still unstable, it might be your motherboard or some other factor holding you back. Even a 15% overclock is still pretty good, though, and you can probably get that without any special equipment other than an enthusiast motherboard.
That closes up this overclocking article. We have several similar articles planned, though we're interested in feedback from the readers. Was this too superficial? Do you want more details on tweaking memory timings beyond what we've mentioned? Or is the mix of benchmarks, settings, and results about right? Let us know. This article was long, with a large portion dedicated to introducing the uninitiated to the art and practice of overclocking. Future articles in this series will focus more on the end results and refer back to the concepts presented here. As always, any recommendations and comments are welcome.
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Deathcharge - Saturday, October 15, 2005 - link
also what do you think of opteron 144 or 146? the 144 are very cheap and they OC quite well apprentlypmorcos - Thursday, October 13, 2005 - link
Before I comment, you should know that I have been overclocking for 8 years now and literally overclocked all but one of the chips you mentioned in the beginning of this very good article. The HT multiplier was new to me with my most recent DFI NF4-SLI-DR board so I found that extremely useful and plan to see if I can up my speeds...but I digress.I think it would be extremely valuable to TRY to put in words the order with which an overclocker should approach making changes to settings. In other words, which is likely to be the most limiting/critical aspect(s) and from there tweak the others to max the system out.
It would be interesting to say, for example, that you start with a "safe" power settings (which is pretty obviously the limiting factor). For example, let's say your CPU and memory are rated at 1.3 and 2.8 V respectively. Why not go straight to "safe" settings for the two and tweak from there? It seems that the most useful piece of information that is NOT provided by anandtech or anyone else for that matter is a voltage and temp graph of stability/viability for these chips. It would be simple to take 3 samples (at a cost) of each chip and run the test with "average" cooling and find out what is "safe". For example if running all stock settings but upping voltages to say 2.4/3.6 V in the example above, you might see stability up to 1.65 / 3.1 V with the parts catching fire at say 1.8/3.3 V or stable at temp readings for cpu/memory of 44/47C but unstable above that. Once armed with these two graphs of information averaged from 3 chips tested the rest is very straight forward.
You simply set the cpu volts to 1.65 and memory to 3.1 V (the safe settings; check real voltages vis bios monitoring) and now you up your fsb and tweak your memory timings and in a few minutes you are running max.
Why do I think this is more valuable that showing us a graph of your results? Because like many I'm squeemish about upping the voltage on my processor and memory. I'm worried much more about the power-on affects than I am the "long-term" effects.
In computers, there are no long-terms for an overclocker. An overclocker's comp is 60% hardware and 40% software. Their greatest joy is in posting results on their favorite forum. I want to know that when I hit the power button...that the 1.7V setting does NOT have a 10% chance of blowing my processor.
My ramblings. Thanks again for another great article from by far the VERY BEST place in the world to find out how computer parts work.
JarredWalton - Thursday, October 13, 2005 - link
Thanks pmorcos.I'm working on the X2 3800+ OC followup, and I've gone back and done further testing of temperatures and voltages. Chips differ, so the real advice I have on that subject is to test your own chip extensively. I've heard of people doing 2.8 GHz on 1.500V with the Venice chips, but mine won't even POST at those settings. I think 1.65 or 1.70V was required to POST, and even then I couldn't run stable benchmarks without more voltage.
I will also be trying to cover a bit more of the "how to" process in the next one. Consider this the foundation, and the next article will refine the approach a bit. Your comments on what you'd like to see more of are definitely welcome, though, and I'll try to address the order and approach I take next.
Concerning another comment: "I want to know that when I hit the power button...that the 1.7V setting does NOT have a 10% chance of blowing my processor." I'm not quite sure I understand the concern or know how to test that. Are you saying that the power on process has more voltage fluctuations and may therefore toast the CPU in the first second? (I haven't had that happen over the past several months of testing this chip and others in overclocked setups.) I must admit that I'm extremely nervous about the 1.850V I used for running at 2.80 GHz, but even then the chip continued to function (for now - heheh).
Cheers!
Jarred Walton
WhipperSnapper - Thursday, October 13, 2005 - link
That was one of the best computer enthusiast website articles that I've read in a long time, but perhaps I don't get around too much. I'd like to hear more about the problems that spilled over to other components, such as the SATA hard drive (mentioned in the Final Thoughts) and whether or not the overclocking can be isolated to the CPU and RAM. I also wondered if there was a reason why you guys used a SATA hard drive and not an IDE drive and whether overclocking requires a SATA hard drive. (I don't see why it would.)
Also, have you guys tried to do any tests using memory stick heatsinks? Do they actually do anything? That subject might make for a worthwhile article on its own--RAM cooling.
aptinio - Saturday, October 8, 2005 - link
bravo! great article. very informative but not too bloated. can't wait to finally upgrade my amd k6-II with 1mb l3 cache on the motherboard! lol!Kougar7 - Thursday, October 6, 2005 - link
Thank you for the excellent, comprehensive, and very thorough article! :-) It must have taken a massive amount of work and time to complete. It’s answered my recent musings about my own Crucial value ram, which looks much nicer now! It’s also solved a question about OCing with recent AMD 64 chips, amongst also correcting a few personal misconceptions I’ve had.I just wish to ask if you plan to include a similar article on OCing with P4s? I personally run a 2.8C (Northwood) @ 3.4 rock solid at the 3.4C’s default voltage, but am now wondering exactly what performance hits, if any, that I’ve taken from having to use a 5:4 CPU:DRAM ratio instead of the previous 1:1, even though I’ve kept it at DDR390 and the timings better than specs.
I’m planning to bench the differences from a 1:1 ratio, a 3:2 ratio at highest speed I can get (sub-DDR333), my current setup, and finally one other setting where I got the value memory to run 2-2-2-6 timings, to get a more solid idea on which performs best with some solid figures.
Although the core and the platform itself both have both changed, I’d still be interested in a Intel processor based test! Perhaps instead of a P4, maybe a Pentium “D” OCing article similar to what you have planned with the X2 3800+? ;-)
I’m very much looking forward to your X2 3800+ OCing review!! You rock :-D Thanks in advance for it!
JarredWalton - Thursday, October 6, 2005 - link
I'm trying to get a socket 775 motherboard that will overclock well with Pentium D 820. Once I get that, I can give it a go. I've also got a Pentium 4 505 and a 540 that I want to run some similar tests on. First, though, I need an appropriate motherboard.clue22 - Thursday, October 6, 2005 - link
so basically what the everybody is saying about the value RAM vs. low latency more expensive RAM is that for the athlon 64 it is basically a waste of money (i.e. you only get about 5% performance gain), but usually spend 100% or more money to get the "better" RAM. i have to build a couple of systems pretty soon and now i believe that my money would be better spent on 2GB of value RAM vs. 1GB of the more expensive stuff. does anyone know of a test that has been run with 2.5-3-3-8-1t vs. 2-2-2-5-1t? also why does every mid-range/gaming/hot-rod price guide ever recommend the either the samsung tccd (or tcc5) or winbond bh5/ch5 based memory if it has so little effect on performance. finally is it even important anymore (if it ever was) to get matched pairs of memory that are bundled together (supposedly manufactured at the same time)? i was looking at some corsair (had good experience with them in the past) xms3200xl RAM but now i think i should get more of their value select memory instead.thanks
RupertS - Wednesday, October 26, 2005 - link
so basically what the everybody is saying about the value RAM vs. low latency more expensive RAM is that for the athlon 64 it is basically a waste of moneyThis may not be a general rule.
It may just be that at this stage of development for GPU's, CPU's and memory, memory has more than enough capacity - it is not the choke point. If GPU and CPU speed were to improve while memory speed stayed the same, you might reach the point where increasing GPU and CPU speed was non-productive for games, while overclocking memory provided large performance improvements.
rabbit fighter - Wednesday, October 5, 2005 - link
Where was this explained? He said the 3200 was better in the first paragraph and that he would explain later, but I can't find the later explanation!