OC my A64 2800... Have a Q.

Lord Banshee

Golden Member
Sep 8, 2004
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Hello all I am new to the forum but been a long time anandtech reader. Anyway here my questions.

I have the 2800+ of the Athlon64 socket 754 and i been experimenting with oc'ing on my vnf-250 mobo. Some question that concern me or just wonders are

1) What is a good temperature for a air-cool(Stock heatsink and fan) Is 55-65*C an ok running CPU during Prime95?

2) How safe is it to up the Voltage to the ram ? i have Corsiar 512MB Value CAS 2.5? And is it even wroth playing with?

3) So far i got 2100MHz stable with 233 CPU Speed and a 1 to 1 ratio for the DRAM. The only thing i increase or change was the CPU speed and upped to CPU Voltage to 1.65 but i am sure it will work with 1.6. I tired running at 2200MHZ w/ 244CPU Speed and 3x Hypertransport and it ran Sisoft Sandra 2004 fine but after about 15 min of doing different things on my computer i got a BSOD. Any ideas on things i can try to make it stable? Would upping the Voltage to the ram help any if it is the ram that cause the BSOD


Thanks in advance,
Chris
 

Lord Banshee

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Sep 8, 2004
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I just did a Prime95 for 2 hours with 238fsb @ 9x = 2142MHz, 3x HT, 1.65v CPU. Stable max temp under load 59*C. Idle 39*C

If you want to know my sandra 2004 scores here they are

Stock 1800MHz 200fsb
Dhrystone ALU = 8308
Whetstone FPU/iSSE2 = 2853/3721
Integer x4 aEMMX/aSSE = 17248
Floating-Point x4 iSSE2 = 18548
RAM Int Buff'd = 2763
RAM float Buff'd = 2763

2142MHz, 238fsb
Dhrystone ALU = 9844 18.5% increase
Whetstone FPU/iSSE2 = 3381/4409 18.5% increase
Integer x4 aEMMX/aSSE = 20437 18.5% increase
Floating-Point x4 iSSE2 = 21814 17.6% increase
RAM Int Buff'd = 3279 18.7% increase
RAM float Buff'd = 3280 18.7% increase

Total of a 18.4% increase in sandra 2004. As is i think this is the max of the Ram before it starts failing. So what you guys think up vdimm +0.1 and see if 244 is stable?

Q. How import is the HT multiplier( the one that can go from 1-5x) I have it at 3 and when i tried setting it on 4x on another overclock i did i got a crash at the Ram Bench in sandra but all other benches were the same as the 3x. Is this HT really not import in A64's becasue it is so efficent or sandra not testing it and i should try testing q3 or something. i would test doom3, but my graphics card is the bottleneck (5900XT).

Thanks

*edit*

Just tried to run 3dmark03 BSOD :(. Ok what you guys think i am going to try a couple different things with my oc at 2100.





 

broly8877

Senior member
Aug 17, 2004
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try using a divider

I'm at 2223MHz (vnf3-250 + 2800)

1.6 vcore, 3x ht, 166 divider

edit: i havent noticed a substantial difference in a higher ht, but it does reduce stability when paired with a high oc
 

broly8877

Senior member
Aug 17, 2004
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Oh, forgot to mention.
60c load temp is way too high, at least imo.
AMD states a max temp for a NC is 70c, 85c for CH -- 60c is just too close to that.
 

Lord Banshee

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Sep 8, 2004
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Yeah I have to play with that later, but that bad thing about that is that you lose memory strength.

My BSOD above was cause by graphics driver. reinstall all fine. But to fine that my 2100Mhz is the most stable right now. I'll play with the divider this weekend and see if it affects my realtime proformnce.


I tested a 3dsmax 6 scene using GI with MentalRay and i get got a 17% faster render with my 2100Mhz OC.

I'll wait tell i am finish testing before i post anymore unless someone responds or i have a problem
 

Lord Banshee

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Sep 8, 2004
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Originally posted by: broly8877

Oh, forgot to mention.
60c load temp is way too high, at least imo.
AMD states a max temp for a NC is 70c, 85c for CH -- 60c is just too close to that.

I thought i read it was 95 before things break and 70 was the Case temp which mine is 28*C.

What kind of temps you getting?
 

Sylvanas

Diamond Member
Jan 20, 2004
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check your heatsink is making proper contact with the cpu, while your doing that pop on some artic silver 5.
 

Lord Banshee

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Sep 8, 2004
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What is average temps of the processor? I am not going to pop it off unless i know with some fact that my temps are too high? And i will have to go buy some artic silver 5.

Q about the artic silver 5, you have to take all old silicon paste off of chip first right? If so what is the best method of doing this.
 

Jhatfie

Senior member
Jan 20, 2004
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Rubbing alcohol does an excellent job of removing old AS5 or other pastes. Since the A64's have the heatspreader, it makes it easy to saturate a lint free clocth with alcohol and wipe off the paste.

Your 20C rise in load temps is fairly high, but pretty much on par with what my 3000+ did with the OEM heatsink. I'd look into alternate cooling if you plan on using more than 1.6v on a regular basis. I am using a Alpha PAL and 80mm fan with my CO core 3000+, which is now at 36C idle and 48C prime95 load at 2.4ghz (1.65v). The OEM heatsink would idle at 45C and laod at 60C with the same vcore.
 

pelikan

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Dec 28, 2002
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I'd use 2.9V on the ram. AS5 will give you slightly better temps, but if you really want to overclock the best heatsink is the new Thermalright XP 90 and its $37. at Jab Tech right now with a choice of fan for $2. more.
I wouldn't worry about the temps, as the sensors are probably not accurate. Just make sure it can run Prime95 for hours during the warm part of the day. If its too hot you will get errors.
 

OMG1Penguin

Senior member
Jul 25, 2004
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If the heatsink feels ouch, then you have to look at your case cooling. If it feels warm/cool, make sure it is on properly. If you know it is on properly, and it is only warm, then you should be fine.
 

BW86

Lifer
Jul 20, 2004
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59c isnt that bad for load considering you still have your stock heatsink and your at a 1.6vcore
 

Lord Banshee

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Sep 8, 2004
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Originally posted by: pelikan
I'd use 2.9V on the ram. AS5 will give you slightly better temps, but if you really want to overclock the best heatsink is the new Thermalright XP 90 and its $37. at Jab Tech right now with a choice of fan for $2. more.
I wouldn't worry about the temps, as the sensors are probably not accurate. Just make sure it can run Prime95 for hours during the warm part of the day. If its too hot you will get errors.



Is that Safe? Stock Voltage is what 2.5 right?

And when i get some money and time i might just want to do that But i probally add mem heatsinks to my video card at the same time and use AS5 on the GPU heatsink aswell....

My case cooling is pretty good if i say so myself. I have a Antec Sonata with 2 120mm fans. 1 120 fan for rear, the other blowing over the heatsink/GPU toward the back. My case should have cool circulation.

Thanks for all the comments guys
 

broly8877

Senior member
Aug 17, 2004
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I got those temps from AMD, AMD states a max temp for a NC is 70c, 85c for CH.
I also have a Sonata, low rpm @ 31c case
Idle CPU @ 33c
Load @ 48c


edit: Stock HSF