3.2 640 @ 4.0 (250 x 16)

[TheMainFrame]

Ok so i finished my Water cooling setup and this is what im gonna stability test tonight

The rig is the one in my sig

Loosend my timings on ram to SPD (3-3-3-8) and running them 1:1 which underclocks them

Uped my CPU voltage to 1.5v and set my FSB to 250

Ive had it stable at 240 on stock voltage but wont budge a hair without some real juice

Temps seem to be 33C-35C idle and 39C-41C load

Load and stability are being tested with Dual Prime95 running

check my sig if you want more details on the WC setup.. follow link

I got a few questions for tommorow after work when i continue...

1.) If it should fail stability how much juice is it safe to give one of these 640's?

2.) Id be more than happy with 4.0... if it is stable can i expect much more from it?

3.) How come in my bios i set my voltage to 1.5v but CPU-Z shows voltage at 1.408v? Is my bios wrong or is CPU-Z wrong? CPU-Z is also showing the wrong bios version... could this be a slightly bad bios flash?

4.) any suggestions regarding anything?

 

[billiam]

what is mbm saying the voltage is?

 

[outhouse]

#3 you got some vdroop normal

if you get reboots up vg a hair and see @whaterver your running

3.2 in 478 runs well at 4 and 4.08 under 1.5 anything over gets unstable

your not far off those marks

 

[batboy]

1. I probably would not go much above 1.55v actual vcore even with watercooling.

2. If you are needing to use that much vcore at 4.0 gig, then you are getting close to the limit. Maybe 4.1 to 4.2 gig assuming you are stable at where you're currently at.

3. Like Outhouse says, most mobos undervolt the Prescott. I would use a monitoring program (MBM5 for example) and look at load vcore. If under load you are consistently undervolting, then use actual vcore. In other words, if 1.5v in the BIOS equals 1.4v actual, then using 1.6v in the BIOS will probably mean 1.5v actual and should be safe.

4. Use RAM voltage of 1.9v and set the timings back to 3-2-2-8. At least until you find the limits of your system, just use the 1:1 memory ratio. I have found the 3:4 ratio don't give you much of a performance gain anyway. You can always go back to that later. I have the same RAM and using 2.0v I was able to easily run 3-2-2-8 at DDR2-667 (3:4 ratio). OCZ is rated for use at 2.0v.

 

[TheMainFrame]

MBM5 dident support my board last time i checked.. are the updates frequent?
If not what is another option?

*edit* Just checked and my Mobo is not on the MBM5 list

 

[batboy]

Check the install CD of your mobo. I thought Gigabyte had some sort of monitoring program that was shipped with the board. Maybe post the question in the Gigabyte mobo section?

 

[TheMainFrame]

Check the install CD of your mobo. I thought Gigabyte had some sort of monitoring program that was shipped with the board. Maybe post the question in the Gigabyte mobo section?

Ill defianatly do that

Thanks

 

[batboy]

Alternatively, CPU-Z does update readings every couple of seconds. You could load the system using a program like PCmark2004 or Sandra burn-in wizard or something like that and bring the CPU-Z window back on top to check vcore.

 

[TheMainFrame]

Alternatively, CPU-Z does update readings every couple of seconds. You could load the system using a program like PCmark2004 or Sandra burn-in wizard or something like that and bring the CPU-Z window back on top to check vcore.

so are you saying that in your opinion CPU-Z is a fairly accurate program?

In other words if i set my bios to 1.5 there is some droop.. so if CPU-Z says its 1.408 then its either right on or not far from?

also.. that was under load... i checked that Vcore during a duel Prime95 session

It runs lower when idle

 

[massraptor]

Have you tried Speedfan?

Have you tried Speedfan?

Speed Fan Here

Have you tried Green Eggs and Ham?

MassRaptor

 

[batboy]

CPU-Z will only report what the mobo sensors signal to the BIOS. How accurate they are is unknown, but it'll give you a reasonable idea of what's going on. Probably the only way to get a totally accurate voltage reading is with a high quality multimeter. If CPU-Z is reading 1.408v at near idle when you have the BIOS set to 1.5v, I'd say it's pretty safe to assume a BIOS setting of 1.55v should be ok (if temps are good).

 

[TheMainFrame]

CPU-Z will only report what the mobo sensors signal to the BIOS. How accurate they are is unknown, but it'll give you a reasonable idea of what's going on. Probably the only way to get a totally accurate voltage reading is with a high quality multimeter. If CPU-Z is reading 1.408v at near idle when you have the BIOS set to 1.5v, I'd say it's pretty safe to assume a BIOS setting of 1.55v should be ok (if temps are good).

So here is an interesting question.. when the bios figures out the stock voltage which i think is 1.385v does it compensate for the droop?

 

[pik4chu]

So here is an interesting question.. when the bios figures out the stock voltage which i think is 1.385v does it compensate for the droop?

Is this stock voltage what the BIOS tells you or what CPU-Z tells you? given all your results so far if the BIOS says 1.385 I'd wager it is reading higher than normal there too. All in all if you really want you know you will need to pick up a multimeter.,

 

[TheMainFrame]

Is this stock voltage what the BIOS tells you or what CPU-Z tells you? given all your results so far if the BIOS says 1.385 I'd wager it is reading higher than normal there too. All in all if you really want you know you will need to pick up a multimeter.,

1.385 is the bios setting that my bios goes to when its on auto.. ive never checked to see if thats what CPU-Z is reading it at.. im assuming with this droop where speaking of it will be in the upper 1.2's tho

1.5 is what i set my bios to for the overclock.. but my CPU-Z reads it at 1.408 under load

and thats not what the bios is reading.. thats what the bios is set at (Theres a diffrence im assuming)

 

[TheMainFrame]

Ok so i got speed fan running now and this is what im seeing

With a clock of 3.2 @ 4.0 (250 x 16)

Bios setting 1.5
CPU-Z reading 1.408
SpeedFan Reading 1.41

Bios Setting 1.525
CPU-Z reading 1.424
SpeedFan Reading 1.42

is it possible my droop is .1v?

and how accurate would a $20 multimeter be?

 

[batboy]

Undervolting 0.1v is quite possible. My Abit IC7 would do that too. I would say you are in the right ballpark with that voltage. Hitting 4 gig with just 1.41v is pretty good.

 

[TheMainFrame]

Undervolting 0.1v is quite possible. My Abit IC7 would do that too. I would say you are in the right ballpark with that voltage. Hitting 4 gig with just 1.41v is pretty good.

athually it wasent stable at the 1.5.. but the 1.525 was stable.. so more like 4g at 1.425

 

[batboy]

Still, a very respectable overclock. Well done.

 

[TheMainFrame]

Had to bump the voltage another hair.. was only stable for 1 1/2 hours with the duel prime 95... got it upto 1.440v and it was running all night (about 7 hours) and was still running smooth when i woke up this morning..

Were looking at like 15 hours of running by the time i get home and check it..

Ill let you know how it goes