• Competitor rules

    Please remember that any mention of competitors, hinting at competitors or offering to provide details of competitors will result in an account suspension. The full rules can be found under the 'Terms and Rules' link in the bottom right corner of your screen. Just don't mention competitors in any way, shape or form and you'll be OK.

Safe max Vcore for PII 720BE?

pieman109

pieman109

pieman109

Soldato
Joined
21 Oct 2002
Posts
7,425
Location
Bexhill on sea
I've currently got one of the above cpus running at 3.5ghz stable using just the multi and Vcore increased to 1.425v, temps are 26c idle/load 38c, but these read higher if a different app is used, but highest i've seen is 45c load.
I've read about how good these chips are at overclocking and was wondering how much higher I could get this one, hence asking about max vcore.
Also, any other guidelines/advice would be appreciated, been an intel bod for quite some time now and these amd based bioses are somewhat different.
Cheers for any info:)

Edit: Any suitable benching apps would useful too so I could compare with the system in me sig.
 
Last edited:
tbh when i had a 720 i contacted amd they said 1.425v max, 70c tcase max.

but it's up to u if u wanna go higher.

i got mine to 3.7ghz with 1.425v
 
Last edited:
gareth170 said:
yeah has i said its up to u what voltage u want to limit the max to. but amd recommands 1.425v max
Click to expand...

What settings other thanVcore did you settle with to get 3.7ghz mate?
I've had a look around and it appears some ppl are shoving up to 1.55v V core into their PII chips.
 
gareth170 said:
just core voltage to 1.425v. multiplier to 18.5x, cpu-nb voltage to 1.25v, nb frequency to 2400mhz..

whats your stock vid? mine was 1.25v
Click to expand...

Vid for this cpu 1.325v

I've had a look at the NB frequency setting in me bios and doesn't give a frequency value, just a set of multis (x5, x6, x7 all the way up to x20) but with out knowing what frequency "auto" is, I don't have a baseline to work from. I notice you also have a gigabyte mobo, could give me some figures to work from, the manual tells me absolutely nothing about this.
Cheers.
 
Last edited:
gareth170 said:
well in that case, 1.450-1.475v should get u 3.6ghz. 1.5-1.525v should get u 3.7ghz.

just a guess
Click to expand...

Would I be correct in thinking as I have an unlocked cpu (BE versh) so by overclocking I'm just raising the cpu multi and keeping the fsb at 200, I don't have increase the NB frequency to 2400mhz, as its frequency doesn't change as it'll be linked to the fsb, but i have to increase the NB voltage a touch?
 
pieman109 said:
Would I be correct in thinking as I have an unlocked cpu (BE versh) so by overclocking I'm just raising the cpu multi and keeping the fsb at 200, I don't have increase the NB frequency to 2400mhz, as its frequency doesn't change as it'll be linked to the fsb, but i have to increase the NB voltage a touch?
Click to expand...
yes its a BE

but increasing the NB frequency improves the memory and L3 cache.. NB frequency can be upped by the multipler
 
Hey pieman109,

glad your getting on with your MM triple core Deneb, 3.5GHz isn't too shabby but I reckon you should be able to get more?

For pure Black-Edition overclocking I don't think you need to know about anything apart from vCore, CPU multiplier and load temps! :D

What is the max vCore value that you are seeing in CPU-z while under load? . . . I would give it as much juice as it needs to get a higher clock stable, the only thing that will hold you back is either the load temps or the motherboards ability to deliver an increased vCore without fluctuating to much.

Once you worked out what frequency needs what vCore then you can proceed onto old-school clocking by manipulating the HT-Ref. and playing with the CPU-NB dividers and voltage and the HT-Link dividers. At default on the Rana triple core I am using both the CPU-NB and the HT-Link should both be 2.0GHz, this value is worked out at 200MHz (Base HT Ref.) x 10, on your chip it may be higher I'm not sure?

Base Ht Ref. is basically the FSB so that's what your gonna be adjusting up and down, if you set it to 250MHz and leave both the CPU-NB & HT-Link at default multi they will be overclocked to 2.5GHz, if you drop both the CPU-NB & HT-Link Multi from [x10] to [x8] they will both be running at stock speed (8x250-2.0GHz), the only thing that will have changed is the CPU will be overclocked more and the Memory will also be overclocked . . .

You will be wanting to combine an increase CPU overclock with an increased CPU-NB overclock. The CPU-NB voltage you need for this increased overclock will depend on the IMC in your CPU, mine does 2.5GHz with about 1.225v. Another thing that may hold you back is the Memory divider you go with, on DDR2 based AM2+ systems the default memory is 400MHz [2:1] which combined with a set of DDR2-1066 will mean you should be able to reach 266MHz HT-Ref. before your memory is being overclocked . . . . to increase the Ht-Ref beyond that and without overclocking the ram further you would just drop the memory divider in BIOS . . .

That's all I can think of for the moment, just take your time as its quite a different system to Core 2, it's taken me about one month to get the basics down so don't expect miracles overnight! :cool:
 
That's all I can think of for the moment, just take your time as its quite a different system to Core 2, it's taken me about one month to get the basics down so don't expect miracles overnight! :cool:[/QUOTE]

Thanks for the info mate, very useful, hada quick read and what I thought has been confirmed. I had to reinstal XP as I reckon I mullered the installation with all the unsuccessful reboots and I'm quite happily sitting here with 3.6ghz at 1.45v vcore, with max load temps of 45c after 3 hours of running prime95. I'll keep those settings for a while and see how the system is for general stability and then try higher after that.
As a general observation, these PII chips seem faster in windows at opening and closing apps, getting on the interweb, etc than my existing C2D e8400 at 3.8ghz, but that could be 'cos this is a fresh instal with nothing else installed/running other than a few benching apps.
Can you recommend a coupla benchiews I can run to compare this system and the one in me sig, just mainly cpu/ram/mobo stuff, I haven't got any vidcard installed to check game performance yet.:)

Edit: Just upped the multi x18.5, now at 3.7ghz at 1.475v vcore, load temps whilst prime95 tesating 46c.
Quite happy with this chip:)
 
Last edited:
pieman109 said:
As a general observation, these PII chips seem faster in windows at opening and closing apps, getting on the interweb, etc than my existing C2D e8400 at 3.8ghz
Click to expand...
The AMD system is lower latency than your Wolfdale system thanks to the AMD on-chip memory controller, that would make itself felt by a general *snappiness!*

I'm not one to recommend benchmarks but CINEBENCH R10 would be a good one to start with! :cool:
 
Last edited:
Right, spoke too soon, prime95 just bombed out so its back to 3.6ghz for the time being. I'll run some of the CINEBENCH R10 to compare the two systems and post back here again in a coupla days.
Thanks for the info Wayne, its appreciated mate.:)
 
pieman109 said:
Just upped the multi x18.5, now at 3.7ghz at 1.475v vcore, load temps whilst prime95 tesating 46c.
Click to expand...
pieman109 said:
Right, spoke too soon, prime95 just bombed out so its back to 3.6ghz
Click to expand...
When you say 1.475v is that what your setting in the BIOS or is that what CPU-z is telling you while it is under load?

46°C full load is great, pump the vCore! :cool:
 
pieman109 said:
I'm quite happily sitting here with 3.6ghz at 1.45v vcore, with max load temps of 45c after 3 hours of running prime95.
Click to expand...
so i was right. :D

i really think 1.5v will do 3.7ghz

the problem with prime95 is that it needs a lot longer running time so u know its fully stable.

use something like LinX which use the cpu to its max. do it for about 1-2 hours.

all phenom II x3 have low temps. also keep your eye on the overall CPU temperature not the core temp...

this is what i got from amd:

Dear Gareth,

Correct, as long as you are within the voltage and temperature guidelines you are ok. The temperature that should be monitored is the overall CPU temperature, not the core temp.

Best regards,
Jesse
AMD Global Customer Care
Click to expand...
 
Last edited:
gareth170 said:
the problem with prime95 is that it needs a lot longer running time so u know its fully stable.

use something like LinX which use the cpu to its max. do it for about 1-2 hours
Click to expand...
Gareth, Prime95 and IBT/LinX are different stability tests . . .

You may think an hour or two or IBT/LinX is rock-solid stable but some of us have found out this isn't the case . . . there is still no replacement for a good old 8 hour Prime95 run, you should try it sometime, the Blend test is good on the AMD platform! :cool:
 
Big.Wayne said:
You may think an hour or two or IBT/LinX is rock-solid stable but some of us have found out this isn't the case . . . there is still no replacement for a good old 8 hour Prime95 run, you should try it sometime, the Blend test is good on the AMD platform! :cool:
Click to expand...
Big.Wayne, i was giving my advice to him. please stop trying to make me look stupid....

as u u said only some people.

but i've found that i could run Prime95 for so many hours on blend without errors where IBT/LinX found errors in the first 10-20minutes...

even the readme file says:
Takes less time to tell if your CPU/RAM is unstable than Prime95 (usually something like 8 minutes Linpack vs 40 hours under Prime95).
Click to expand...
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom