Investigations into Socket 939 Athlon 64 Overclocking
by Jarred Walton on October 3, 2005 4:35 PM EST- Posted in
- CPUs
Introduction
Note: This article is an in-depth look at overclocking. We'll cover how to do it, what sort of performance you can achieve, problems and potential solutions, etc. Overclocking can be frustrating, rewarding, fun, and dangerous. We don't mean "burn the house down" dangerous, but you could certainly end up ruining some or all of your computer components. We take no responsibility for any difficulties or losses 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 manufacturers of the parts that we are using are also not accountable for any loss/damage that may occur - most companies void your warranty for overclocking. It's a risk, and it's your risk - proceed with caution. Finally, overclocking is never a "guaranteed result". You may or may not match the results that we achieve. We'll be happy to offer suggestions if you need them, as will many of our forum members. Patience and research are part of overclocking as well, so please understand that you may have to do some work on your own. If you can accept those warnings, we hope that you enjoy this article.
Back in the day, overclocking was in some ways simpler than what we see now. You would typically buy a mid-range processor and then try to increase the bus speeds as much as possible in order to get the most performance out of your system. Older Pentium chips also allowed you to change the multiplier, so with some luck, you might get your 2.5X multiplier on a Pentium 166 up to 3.0X, resulting in a 33 MHz overclock. Other than a few special chips like the Pentium M and Athlon FX, increasing multipliers is no longer possible. The modification of bus speeds can still be used, but it isn't necessarily the best or only way to try to overclock your system. We have mentioned overclocking performance in many articles, but we haven't taken the time to really explore all the options out there. We also know that current Intel and AMD setups have very different options and performance when overclocking is used, so we want to look at that as well.
Before we branch out into AMD vs. Intel comparisons, however, let's talk about the past top performers. The Celeron 300A is fondly remembered by many people, and with good reason. Yes, we have had some other good parts in the intervening years, like the 2.4 GHz Northwood cores, the low end Prescott cores, and the Athlon XP-M Barton parts. However, when you look at the 50% overclock of the Celeron 300A (and it wasn't just possible, it was common), none of the other parts have really ever approached that level of overclocking without some serious investment in cooling options. (Some people even managed to get the 300A to 504 MHz - an amazing 68% overclock!) Northwood's 2.4 GHz to 3.2 GHz is still an impressive 33% overclock. The 2.4 GHz to 3.6 GHz Prescott overclock (using the 2.4A) actually matches the 50% of the 300A, but you sacrifice some features (HyperThreading and high FSB speeds) with the lower model parts. Meanwhile, the overclocking darling that was the XP-M 2500+ "only" managed a typical overclock of 1.87 GHz to 2.4 GHz, a 29% overclock.
That brings us to the part that we're investigating today. It is arguably the best overclocking platform since the old Celeron 300A: AMD's Venice core. One thing that we didn't mention above is the role that price plays for many overclockers. Sure, the Athlon-FX can reach clock speeds and performance that most other chips only dream about, but at a cost of roughly $900 just for the processor, a lot of people will only read about it. What made the 300A so attractive was that it was not only a monster overclocking chip, but it cost around $150 and competed with $500 chips. That's why the 2.4C and 2.4A Pentium 4 are also well regarded; they cost under $200 and could compete with chips that cost two to three times as much. The price of entry for the cheapest Venice core (the 3000+) is once again very low; $120 for the OEM model, or $145 for the retail version.
We'll get into the details more in a moment, but for now, we'll just say that the 3200+ may actually be a better choice, and that's what we are using for this article. We are also using the retail model, and some people will say that retail parts tend to overclock better than the OEM chips. We'll simulate 3000+ overclocking using a 9X CPU multiplier, but that may or may not be an entirely accurate representation of 3000+ overclocking performance. In general, though, what we're hearing is that almost all of the Venice cores can run at very high clock speeds with a bit of effort, so there isn't a huge difference between 3000+ parts binned for 1.8 GHz and 3800+ parts binned for 2.4 GHz. AMD has simply set the package to use a maximum 9X multiplier on the former and a 12X multiplier on the latter. Talking about CPU multipliers leads us into the real meat of the discussion, though, so let's get into it.
Note: This article is an in-depth look at overclocking. We'll cover how to do it, what sort of performance you can achieve, problems and potential solutions, etc. Overclocking can be frustrating, rewarding, fun, and dangerous. We don't mean "burn the house down" dangerous, but you could certainly end up ruining some or all of your computer components. We take no responsibility for any difficulties or losses 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 manufacturers of the parts that we are using are also not accountable for any loss/damage that may occur - most companies void your warranty for overclocking. It's a risk, and it's your risk - proceed with caution. Finally, overclocking is never a "guaranteed result". You may or may not match the results that we achieve. We'll be happy to offer suggestions if you need them, as will many of our forum members. Patience and research are part of overclocking as well, so please understand that you may have to do some work on your own. If you can accept those warnings, we hope that you enjoy this article.
Back in the day, overclocking was in some ways simpler than what we see now. You would typically buy a mid-range processor and then try to increase the bus speeds as much as possible in order to get the most performance out of your system. Older Pentium chips also allowed you to change the multiplier, so with some luck, you might get your 2.5X multiplier on a Pentium 166 up to 3.0X, resulting in a 33 MHz overclock. Other than a few special chips like the Pentium M and Athlon FX, increasing multipliers is no longer possible. The modification of bus speeds can still be used, but it isn't necessarily the best or only way to try to overclock your system. We have mentioned overclocking performance in many articles, but we haven't taken the time to really explore all the options out there. We also know that current Intel and AMD setups have very different options and performance when overclocking is used, so we want to look at that as well.
Before we branch out into AMD vs. Intel comparisons, however, let's talk about the past top performers. The Celeron 300A is fondly remembered by many people, and with good reason. Yes, we have had some other good parts in the intervening years, like the 2.4 GHz Northwood cores, the low end Prescott cores, and the Athlon XP-M Barton parts. However, when you look at the 50% overclock of the Celeron 300A (and it wasn't just possible, it was common), none of the other parts have really ever approached that level of overclocking without some serious investment in cooling options. (Some people even managed to get the 300A to 504 MHz - an amazing 68% overclock!) Northwood's 2.4 GHz to 3.2 GHz is still an impressive 33% overclock. The 2.4 GHz to 3.6 GHz Prescott overclock (using the 2.4A) actually matches the 50% of the 300A, but you sacrifice some features (HyperThreading and high FSB speeds) with the lower model parts. Meanwhile, the overclocking darling that was the XP-M 2500+ "only" managed a typical overclock of 1.87 GHz to 2.4 GHz, a 29% overclock.
That brings us to the part that we're investigating today. It is arguably the best overclocking platform since the old Celeron 300A: AMD's Venice core. One thing that we didn't mention above is the role that price plays for many overclockers. Sure, the Athlon-FX can reach clock speeds and performance that most other chips only dream about, but at a cost of roughly $900 just for the processor, a lot of people will only read about it. What made the 300A so attractive was that it was not only a monster overclocking chip, but it cost around $150 and competed with $500 chips. That's why the 2.4C and 2.4A Pentium 4 are also well regarded; they cost under $200 and could compete with chips that cost two to three times as much. The price of entry for the cheapest Venice core (the 3000+) is once again very low; $120 for the OEM model, or $145 for the retail version.
We'll get into the details more in a moment, but for now, we'll just say that the 3200+ may actually be a better choice, and that's what we are using for this article. We are also using the retail model, and some people will say that retail parts tend to overclock better than the OEM chips. We'll simulate 3000+ overclocking using a 9X CPU multiplier, but that may or may not be an entirely accurate representation of 3000+ overclocking performance. In general, though, what we're hearing is that almost all of the Venice cores can run at very high clock speeds with a bit of effort, so there isn't a huge difference between 3000+ parts binned for 1.8 GHz and 3800+ parts binned for 2.4 GHz. AMD has simply set the package to use a maximum 9X multiplier on the former and a 12X multiplier on the latter. Talking about CPU multipliers leads us into the real meat of the discussion, though, so let's get into it.
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Lonyo - Tuesday, October 4, 2005 - link
NO, DON'T, UNLESS YOU HAVE SOMETHING BETWEEN YOUR FINGER AND THE PASTE.Arctic Silver 5 instructions:
DO NOT use your bare finger to apply or smooth the compound (skin cells, and oils again).
JarredWalton - Tuesday, October 4, 2005 - link
Er... I didn't use Arctic Silver. Just the grease that came with the XP-90. I suppose there might be some thermal compounds that would be bad to touch. RTFM, right?Anyway, I'm not particularly convinced of the effectiveness of stuff like Arctic Silver. At one point, there was some story about how the AS batches for a while didn't actually contain any silver because the manufacturing company was skimping on costs (unbeknownst to Arctic Silver or their customers). I could be wrong, but I'm half-convinced AS is just a placebo effect. :)
poohbear - Tuesday, January 3, 2006 - link
that wasnt arctic silver, that was another company entirely (name eludes me since it was 2+ years ago)PrinceGaz - Tuesday, October 4, 2005 - link
Regardless of the compound, you shouldn't touch it with your finger for the reason stated-- skin cells and grease from your finger will be left on the grease and they act as a barrier that reduces thermal-conduction. The simplest way to avoid this is to put a clean plastic bag over your hand before touching the compound as that will prevent any contamination.Regardless of what you say about AS5, numerous reviews of thermal-compunds have shown that compared to the the standard grease supplied with AMD boxed processors, AS5 alone can lower temperatures by a few degrees C. Given how cheap AS5 is compared with a decent heatsink (like the XP-90), it is a very good idea to get some AS5 if also buying a better HSF than what is supplied with the CPU. Using the grease supplied with the CPU or heatsink is a false economy.
THG64 - Tuesday, October 4, 2005 - link
From my own experience I would say the BIOS is at least as important as the hardware itself.My A8N using 1004 final BIOS can run my A64 3200+ @ 2500 MHz (10 x 250, 1.4125V) and the memory at 208 MHz 1T (2x 1GB MDT DDR400 2.5-3-3-8). There is no chance to get a higher frequency running because I get memory problems at anything above 250 MHz (known as 1T bug). I tested the memory up to 217MHz so its not the limiting factor.
Over the months I made many attempts to upgrade BIOS to newer versions and had no luck at all. The last version were even more interesting because of the A64 X2 support. No chance to get even up to 250MHz base. Only the reason has changed it seems. I made a HD upgrade in between and switched from a PATA drive to a SATA drive. This made it even worse.
From 1005 to 1010 the BIOS limited the overclocking to 215 to 220 MHz through reworked memory options. After 1010 the memory isn't the problem anymore or at least not the main problem. Windows is loading until desktop and while the OS is still loading in background the HD LED stays on and the system freezes.
As mentioned in the conclusion the SATA controller seems to limit the possible o/c.
If there would be a lowcost PCIe SATA controller I would surely give it a try but at the moment I stay with 1004 and and more or less working SATA drive at 250 MHz.
lopri - Tuesday, October 4, 2005 - link
Hi,I'm currently running X2 4800+ in my rig. I think I can safely OC it to 2750MHz. But the thing is, my RAM can only do 220MHz.. And the mobo doesn't support anything other than DDR400, DDR333, DDR266. (A8N-SLI Premium)
What are the penalty of running a half-multi? I understand a half-multi won't get you the ideal memp speed, but in my situation I can make up for it by being able to raise the HTT some more. Basically I have following options.
CPU (Max): 2750MHz @1.475V
RAM (Max): 220MHz @2.75V (2-3-2-5-1T)
Therefore, here is what I can do:
1. 10.5 x 261: This gives me CPU 2741MHz and memory 211MHz. (from CPU-Z reading)
2. 11 x 250: This give me CPU 2750Mhz and memory 196Mhz. (from CPU-Z reading)
If I run Sandra I get almost the same CPU score from both settings. But I get a quite bigger memory bandwidth score from the Setting #1. In ideal world (that is, if only the final achieved speed matters), I definitely think the Setting #1 is better. I'd like to know if there is any "inherent" penalty attached to non-integer multipliers.
Could you help me out? Thanks a bunch!
lop
JarredWalton - Tuesday, October 4, 2005 - link
At one point in time, the half multipliers didn't really work properly. They were just hiding some behind-the-scenes memory and bus tweaks. CPU-Z apparently doesn't report this properly. Anyway, if the system runs stable in either configuration, take the configuration that performs better. (Run a variety of tests - memory bandwidth alone doesn't tell the whole story.)Sunrise089 - Tuesday, October 4, 2005 - link
How important is that XP-90? I am wondering if you all feel it is necessary, feel it is necessary for long term safety, or really feel the $45 would be better spent elsewhere?P.S. - Thanks Anandtech. 3000+, X-800 GTO2, and value RAM costs about $400, and overclocked performs about as fast as a stock speed FX-55, x850 xt-pe, and high-end RAM costing $1000+. Your last two updates alone could have saved someone $600.
JarredWalton - Tuesday, October 4, 2005 - link
You can get the XP-90 and a 92mm fan for about $40 shipped, but what's $5? How important is it? Well, I think you could probably get an extra 100 to 200 MHz relative to the retail HSF. I'll be working on testing a few cooling options in a future article. The XP-90 is quieter than the retail fan, but other than that... I'll have to see what difference it makes.da2ce7 - Tuesday, October 4, 2005 - link
When I over clocked my X2 3800+ I got up to 2.6ghz, at 1.45V;But What I am really want to know about it the both the “safe” and “generally stable” cup temperatures, a table of temps from below 20ºC to 80ºC, where the core goes up in smoke (well maybe not that), would be most helpful.