Needs some help from the overclockers

[lemosley01]

I just built a new rig about 2 weeks ago:

Abit KN8-SLI

Opteron 165

2GB G.SKILL HZ

500W Ultra X-Finity.

 

Here is my problem. I have finally got around to overclocking it and my Opteron is 'only' stable at 2250 MHZ (stock is 1800MHZ) @1.35 V (default voltage). The Opterons are noted for excellent overclockability - it seems to be more or less standard to get to at least 2.5GHZ @1.35V. I have upped the voltage to as high as 1.49V but that has only gotten me as far as 2450 MHZ, and I'm not even sure THAT is stable. Yes, I'm greedy. I want more. MUCH more.

 

I was wondering if anyone has a socket 939 Athlon that is overclocked that I could try out in my board to try and narrow down if I've got a 'bad' chip or a crap board.

 

Anyone?

[Rally Pat]

Actually, you are wrong about all Opterons being good at overclocking. There are ones taht have to have a certain core that are good at being overclocked. The rest of them are shit. I am an AMD guy, so I cant really help you beyond that.

[lemosley01]

Actually, you are wrong about all Opterons being good at overclocking. There are ones taht have to have a certain core that are good at being overclocked. The rest of them are shit. I am an AMD guy, so I cant really help you beyond that.

 

Thanks. My perusals of the various forums indicate differently. Perhaps the latest steppings aren't as good as earlier steppings, but so far the lowest I've seen at default VCore is around 2400MHZ.

[Rally Pat]

Check out http://www.gideontech.com .

 

GideonX is a great guy and wrote an amazing article on his persuit of Opteron overclocking.

[Rally Pat]

http://forums.gideontech.com/index.php/topic,32644.0.html

[morabu]

please tell us your not using a factory heatsink/cooler?

[mmrmnhrm]

I was just about to say something to the effect of "How are you getting rid of the heat" when morabu chimed in. Heat is *by far* the number one enemy of a good overclock. That's why I switched to watercooling in the first place.

[iwishiwascool]

please tell us your not using a factory heatsink/cooler?

 

$20 bucks says he is.

[Rally Pat]

er...i gave you all this help under the assumption that you were running aftermarket cooling...did I waste my time?

[thorne]

2.5 on a opteron is not unherd of. btw Opteron is AMD! ......

you need a top notch heatsync.

[Rally Pat]

0_o wow....i totally just dumbed myself down 800 levels, I totally knew that was an AMD chip...

 

*bangs head against wall for the next hour*

[lemosley01]

Yes I am running the stock cooler. The stock cooler on an Opteron 165 (a dual core chip in case you are not familiar with it) is a VERY good cooler - at least equivalent to an XP-90c. I'm not a noob - I actually know what I'm doing and I have narrowed this down to the chip or the board.

 

Many many people have hit 2700MHZ+ with stock cooling and not much more voltage (if any).

 

Here is information on temps.

 

At full load (dual prime95s) running at stock speeds and voltage, the chip will peak at 42c. @2250 MHZ at stock voltage it will also peak at 42C. @1.45V at 2400MHZ, it will peak at 45C. Like I said, the stock cooler on the dual core CPUs is a very good unit. I could get better with a Zalman 9500, but, so far, there is no need to do so.

 

Heat is not the problem here. If I bump the voltage up, then I can reach about 50 MHZ higher than before. If heat were the problem, no amount of voltage increase would help.

[smokin5s]

an upgraded fan makes all the difference in the world... I paid like 60 dollars for mine and it's huge... but it's worth it's weight in gold....

 

I never understood people overclocking their processors.... dude, if you have a 939 chipset board, you have 2Ghz FSB.... which already makes your machine fast as hell.... enjoy what you have... no sense in killing the life expectency of the processor because you want to squeeze out 200 more Mhz that you won't even notice.

[lemosley01]

an upgraded fan makes all the difference in the world... I paid like 60 dollars for mine and it's huge... but it's worth it's weight in gold....

 

I never understood people overclocking their processors.... dude, if you have a 939 chipset board, you have 2Ghz FSB.... which already makes your machine fast as hell.... enjoy what you have... no sense in killing the life expectency of the processor because you want to squeeze out 200 more Mhz that you won't even notice.

 

I've never understood people who modify their cars to make 1000HP for the street. After all, if you already have 300+ HP, enjoy what you have.

 

It is exactly the same mentality.

 

HTT speed doesn't make that much difference. Testing has already been done to that shows that HTT between 600 and 1000 doesn't help much.

 

I assume you are referring to the processor speed. The stock speed is 1800MHZ on an opteron 165. Most of them seem to be capable of 2500MHZ - that is a 40% speed increase, and yes, you will notice it. At 2250 MHZ, my machine is noticably faster in Winblows than @1.8GHZ.

 

Raising the speed of the CPU without having to overvolt it will not harm it, provided you keep the temparatures under control. All the different speeds of the CPUs are cut from the same wafer and then binned. There is no difference between a 1.8GHZ opteron and a 2.4 GHZ Opteron 180 other than the 2.4 GHZ opteron passed the tests @2.4 GHZ as opposed to 1.8GHZ.

 

Stop perpetuating the myth that overclocking will kill your machine. It's a lot less likely to nuke your rig than putting a 100 shot on a car.

 

As far as stock cooling goes, the stock heat-pipe HSF that ships with retail dual-core chips (mine is retail) is clearly good enough for the 2.4GHZ with some margin of safety built in. Remember these processors have 3 year warranties and are server chips - AMD doesn't want them to fail prematurely due to heat. Here is a link to a comparison of the stock HSF vs. other coolers (the cooler I have is the 'Stock Athlon Heatpipe HSF').

 

http://www.madshrimps.be/?action=getarticle&number=10&artpage=1822&articID=419

[Guest compudaze]

Sometimes you just get a turtle. If you really want more I would sell it and buy another if that's the case. What stepping is your Opteron?

 

Have you made sure the motherboard and memory aren't holding you back?

 

Turn the CPU multiplier down to 6 or 7 and set the memory to DDR200 (or the lowest memory divider), set HTT to 3x (or 600mhz) and see how high the HTT base will go until it stops booting. Keep in mind you'll have to use the CMOS reset jumper when/if you reach this point. I easily run a 290mhz base HTT with a 3x multiplier on my NF3 board. I could go as high as 320mhz if my CPU could go farther. Also keep in mind you want to keep the HTT at or below 1000. 200mhz base use 5x multiplier, 201-250mhz base use 4x multiplier, 251-333mhz base use 3x multiplier, etc. If you can't get much higher than 280mhz then it could be your motherboard that's holding you back. If this is the case you can opt for a better board or get the Opteron 170 which has a 10x CPU multiplier.

 

You also want to make sure your memory is running at or below it's rated speed. You can accomplish this by using the memory dividers in the bios. Also make sure the memory is running the correct timings. Using 'Auto' for timings sometimes doesn't always work right. Also, if you're trying to overclock the memory, you may need to loosen the timings.

 

On a dual-core CPU I wouldn't pump more than 1.45volts into it on air cooling. 1.5-1.55v is the max I would use on a single core CPU on air cooling. I'm only refering to 90nm core Athlon64/Opertons here. The 130nm based cores are different.

 

 

 

 

Just for the anti-stock heatsink/fan boys out there. I run my Athlon64 3000+ (1.8ghz) at 2.6ghz on the stock HSF and it's 100% stable. Tested 48+hrs in Prime95 and another 48+ hours in 3dmark2005.

[lemosley01]

Sometimes you just get a turtle. If you really want more I would sell it and buy another if that's the case. What stepping is your Opteron?

 

Not sure on the stepping. I haven't pulled the HSF, and I (like a dumbass) forgot to write the stepping down.

 

Have you made sure the motherboard and memory aren't holding you back?

 

That was the purpose of finding a CPU that had a known overclock limit - to see if I could reach it with my MB. There is the very real chance that it is the motherboard. The board is a KN8-SLI. I'm thinking about duying a DFI Expert and seeing what happens.

 

I'm confident it isn't the memory, since I am not overclocking that. I've had the dividers turned down to keep it between 200 and 250 MHZ (this memory was stable at both 200 and 250 MHZ for days with stock CPU speeds). I have also had the dividers at 1/2, so the ram was running well below it's rated speeds.

 

Turn the CPU multiplier down to 6 or 7 and set the memory to DDR200 (or the lowest memory divider), set HTT to 3x (or 600mhz) and see how high the HTT base will go until it stops booting. Keep in mind you'll have to use the CMOS reset jumper when/if you reach this point. I easily run a 290mhz base HTT with a 3x multiplier on my NF3 board. I could go as high as 320mhz if my CPU could go farther. Also keep in mind you want to keep the HTT at or below 1000. 200mhz base use 5x multiplier, 201-250mhz base use 4x multiplier, 251-333mhz base use 3x multiplier, etc. If you can't get much higher than 280mhz then it could be your motherboard that's holding you back. If this is the case you can opt for a better board or get the Opteron 170 which has a 10x CPU multiplier.

 

HTT maxes at 305 MHZ - this was the first thing I tested. Using HTT 2 or 3x multiplies and a 200 memory divider (on my board 200 would be = 100 on other boards).

 

Using clockgen, I can run 250MHZ HTT stable at 1.35V. For every .01 voltage I give it, I seem to get about another 50 MHZ, up to 1.45V where I can get 2450 MHZ. However, the heat at that voltage doesn't seem worth the small gain.

 

From this testing, I don't think it is my motherboard - if it were, it seems like it wouldn't scale like that, no matter how much voltage I threw at it.

 

I run prime/sp2004 with the stress CPU option. Core 0 is the one that fails, although, if I ramp up enough, both cores will fail. When Core 0 fails, it is usually in under a minute.

 

Just for the anti-stock heatsink/fan boys out there. I run my Athlon64 3000+ (1.8ghz) at 2.6ghz on the stock HSF and it's 100% stable. Tested 48+hrs in Prime95 and another 48+ hours in 3dmark2005.

 

That new HSF from AMD is a really nice piece, isn't it?

 

Thinking I just got a turtle. Oh well, that's how the chips fall sometimes, and right now, I've got a 25% overclock, so that's not bad for free. The new box is way faster than my old AXP 2500+ @2100MHZ, so I'm pretty happy with it.

[Guest compudaze]

Yup, sounds like it's just your CPU.

 

My Athlon64 3000+ at 1.8GHz was noticibly faster than my old AthlonXP 3200+ setup. I know how it feels to want to hit that 50% overclock like the good old days of the Celeron 300A. As a matter of fact, I still have a few Celeron 300A chips laying around I could never get rid of ;p

 

To stress test with Prime95 just make sure you're running two seperate instances of it from two different folders. Within Windows taskmanager you can set the first process to CPU0 and the second process to CPU1. That way both CPUs will be maxed at 100%. If you can run Prime95 for 24+ hours you can consider your CPU overclock stable. Now, how the rest of your system reacts to the overclock is another story.

[lemosley01]

Yup, sounds like it's just your CPU.

 

My Athlon64 3000+ at 1.8GHz was noticibly faster than my old AthlonXP 3200+ setup. I know how it feels to want to hit that 50% overclock like the good old days of the Celeron 300A. As a matter of fact, I still have a few Celeron 300A chips laying around I could never get rid of ;p

 

To stress test with Prime95 just make sure you're running two seperate instances of it from two different folders. Within Windows taskmanager you can set the first process to CPU0 and the second process to CPU1. That way both CPUs will be maxed at 100%. If you can run Prime95 for 24+ hours you can consider your CPU overclock stable. Now, how the rest of your system reacts to the overclock is another story.

 

I have Prime setup for multiple instances (you have to create shortcuts, since, by default, it won't let you launch more than one).

 

However, SP2004 is a prime-frontend as far as I can tell, and gives you a good deal more info than prime does - clock speed, ties into motherboard monitor, lets you set affinity from the interface, etc. Much nicer program.

[smokin5s]

N2O with the correct safety equipment is safe... I guess if you can keep your processor cool enough, it's safe enough... as far as noticing the speed increase... I really doubt it.. in thereoy it is faster, and for short bursts it is, but once the processor heats up, you might read a faster processor speed, but your machine runs slower, has greater chances of locking up, and can cause damage to your processor.

 

as far as moding cars... all 3 of my vehicles are stock... ;-)

[Guest compudaze]

as far as noticing the speed increase... I really doubt it.. in thereoy it is faster

Noticing the difference is very possible. Not all humans are created equal. Just take a room full of people and turn off the lights. Not everyone's eyes will adjust the same or at the same speed.

 

Booting into Windows 5 secs faster may not be much of a difference for someone to even care about, but I noticed it. Loading up OpenOffice in 5 secs instead of 9 is noticable for me. At first I thought it was just me, wanting it to be faster. I actually timed it to ensure there was an increase in speed. But for some people, a 5-10sec difference in doing something on their PC isn't noticable or they plain don't care. 5-10sec over two hours or even a day quickly adds up.

 

and for short bursts it is, but once the processor heats up, you might read a faster processor speed, but your machine runs slower

I don't see how the CPU will run slower when it's hotter. This isn't a heatsoaked car. A CPU, to be simple, is a calculator. If it's too hot it's calculations will have errors. Worst case (besides frying the CPU) is the CPU will make such a bad calculation error it will hardlock the maching forcing a reboot. That's why Prime95 is a pretty good test for CPU stability. If you're just over the heat or speed limit of the CPU, prime95 will error out with a bad calculation. If you're too far over the limit the whole machine will lockup or BSOD.

 

I borrowed a Zalman 9500 CPU cooler just to see how much difference it would make for temps when I first built my new rig. It dropped my 100% load temps by 10C. Now my CPU performed the exact same (using various benchmarking utilities) at 2.6ghz at my previous temps and at 10C cooler. Now even though it dropped my temps by 10C I still couldn't clock the CPU past 2.6ghz. The chip is the limiting factor for me, not heat.

 

has greater chances of locking up, and can cause damage to your processor.

Simply overclocking your CPU does not give great chances of locking up. My CPU has the same exact chance of locking up at 2.6ghz then it does at 1.8ghz. If there were a better way for me to prove it, I would. However, Not all CPU's are created equal. Someone elses CPU may only be stable up to 2.4ghz. So if they were to choose to run it past the limits of the CPU then it has greater chances of locking up.

 

Damaging the CPU from overclocking is dependant upon how you look at things. You will be shortening the lifespan of the CPU from the added heat and voltage from overclocking. Who's really going to be using the same CPU 5 or 8 years down the road, let alone 10 or 13? If you're running the CPU past it's stable range then yes, you will shorten the lifespan even more or kill it prematurely.

 

dude, if you have a 939 chipset board, you have 2Ghz FSB.... which already makes your machine fast as hell

Just to note... The socket 754/939 chips don't have an FSB. Fron-side buses have been done away with for these chips. HyperTransport (HT), formerly known as Lightning Data Transport (LDT) is the replacement technology. Similar, but different. But my point is that there is a specific name for the bus that connects the CPU to the northbridge for these chips. G5 CPUs use HyperTransport as well.

[Razorback]

The best advice I can give is do it gradually. Do you have good case airflow? (Cooling is obviously VERY important) What heatsink are you using? I watercool both my CPU and the GPU so I can't offer fair comparisons to an air cooled system, but with any overclocking, make sure your PSU can handle it, your RAM can handle it, make sure you have the temperatures for overclocking, and just go a little bit at a time. The overclock will only be as good as your weakest piece. It doesn't mean it's the chip. I have my Athlon 64 San Diego 3700+ @ 1.60V running at 2.81GHz rock solid stable, but I have good RAM, a good board, a True Power 480W PSU and watercooling, and my water pump is run by a UPS instead of pulling the current off the PSU rails.

 

I'm sorry I don't have enough time to read this entire thread as I'm at work, but I hope that might give you a bit of direction.

[JaSSon]

The best advice I can give is do it gradually. Do you have good case airflow? (Cooling is obviously VERY important) What heatsink are you using? I watercool both my CPU and the GPU so I can't offer fair comparisons to an air cooled system, but with any overclocking, make sure your PSU can handle it, your RAM can handle it, make sure you have the temperatures for overclocking, and just go a little bit at a time. The overclock will only be as good as your weakest piece. It doesn't mean it's the chip. I have my Athlon 64 San Diego 3700+ @ 1.60V running at 2.81GHz rock solid stable, but I have good RAM, a good board, a True Power 480W PSU and watercooling, and my water pump is run by a UPS instead of pulling the current off the PSU rails.

 

I'm sorry I don't have enough time to read this entire thread as I'm at work, but I hope that might give you a bit of direction.

 

I've gotten mine to 2.9 on air.

[lemosley01]

The best advice I can give is do it gradually. Do you have good case airflow? (Cooling is obviously VERY important) What heatsink are you using? I watercool both my CPU and the GPU so I can't offer fair comparisons to an air cooled system, but with any overclocking, make sure your PSU can handle it, your RAM can handle it, make sure you have the temperatures for overclocking, and just go a little bit at a time. The overclock will only be as good as your weakest piece. It doesn't mean it's the chip. I have my Athlon 64 San Diego 3700+ @ 1.60V running at 2.81GHz rock solid stable, but I have good RAM, a good board, a True Power 480W PSU and watercooling, and my water pump is run by a UPS instead of pulling the current off the PSU rails.

 

I'm sorry I don't have enough time to read this entire thread as I'm at work, but I hope that might give you a bit of direction.

 

Temps are ok - at full load at up to 1.45 V it it never exceeds 49c (this is working both cores with Sp2004). I have seen it fail at 45c with different clockspeeds, so, at this point, cooling is not the issue. Adding more voltage will allow a previously unstable clockspeed to be stable.

 

I'm pretty sure the PS is fine - I plugged a multimeter into the 12v rail while running it under load and there were only very slight fluctuations, and the voltage was held over 12v at full load.

 

My only doubt is the motherboard, but I suspect that is not my issue. I may sell it and by a DFI anyhow, since it is a better all-around board.

[smokin5s]

ehhh nevermind... it's not worth it... when it breaks, don't whine to me.

[Guest compudaze]

I give up... you do what you want...

I think that's a very good idea.

 

just a note if you don't think that overheating can affect your processors performance or locking up then maybe you shouldn't be giving out PC advice :-)

Overheating is one thing. Running your overclocked CPU within mfg. specs is another. Overheating will cause a system to lock up, which is what I said.

 

if you don't belive me... take off your heatsink and fan.... afterall you don't need to keep it cool because the warmer it gets the faster it should run right? ;-)

It's not that I don't believe you. Simply put, you're wrong. Not once did anyone say to not to keep it cool. Nor did anyone say the warmer is gets the faster it gets. My point was it only needs to be kept cool to a certain point. Heat will not affect performance unless you pass the treshhold. After this threshhold, you will get lockups.

 

please read on the page where it talks about 2000 bus speeds. http://www.amd.com/us-en/Processors/ProductInformation/0,,30_118_9485_9487^9493,00.html

Not once does AMD reference "Front-Side Bus" on that page. The System Bus runs at 2000MHz DDR and it's called HyperTransport technology.

 

anyways, the whole point of my post in the first place is if you want a faster machine, guy buy a faster processor... don't try to overclock it. Your processors are rated at a certian clock speed for a reason... and no it's not so AMD can make you pay more for a faster unit.

Although it may be easy for you to drop $1000 on a fast CPU seeing how you are the lead IT department guy for one of the largest companies in central Ohio and you went to school for electrical engineering. But for me, it is not. The difference between my CPU, which is rated at 1.8GHz running at 2.6GHz, and a CPU which is rated at 2.6GHz, besides price, is that the rated 2.6GHz CPU can make that speed on 1.35/1.4 volts whereas I much add more voltage to make the same speed. And I'm not saying all rated 1.8GHz CPUs will hit 2.6GHz either, it's the luck of the draw and a chance I'm willing to take to save money. The added voltage and speed/heat I put on my CPU is still within AMDs specs for these chips. Now my $120 CPU matches your $1000 CPU (or is extremely close) in performance for a fraction of the price. So what if your CPU lasts 10 years and mine only lasts 8 (due to overclocking). I doubt I'll still have it by then anyhow.

 

as far as noticing it... I already stated, you will notice short bursts of speed but not long term because your processor runs hotter and will cause faults... if you still want to overclock it... get an upgraded cooling fan and get case fans. You will thank me later.

There will be no performance difference at the same speeds when comparing a chip that runs 45C and a chip that runs 55C. Cooling is important to keep temps within specs or cooler if you want, but it's not the end all/be all of overclocking. The stock cooler serves me just right at 2.6GHz. However, It may not for the next guy.

 

But what do I know... I just lead the IT department for one of the largest companies in central Ohio and went to school for electrical engineering... so I guess I wouldn't understand how a "calculator" works.

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