Pentium 4 660: Initial Overclocking Results

[jpeyton]

Screenie

Dual Prime95 stable.

These are my initial results using the following open-air test bench:

Hardware:
P4 660
Zalman 7700AlCu + AS5
Abit AS8
PDP XBL 1GB (512MBx2) PC3200 (Slots 2/4)
ATI RageXL PCI
Seagate 40GB PATA
LG 48X CD-ROM
Fortron 550W (Dual 12V Rails)

BIOS Settings:
VDIMM 2.7v
VCore 1.45v
VAGP 1.55v
Game Accelerator A-A-A-D-D (PAT Enabled)
NBFSB 667
DRAM Ratio 1:1
DRAM Timings 2.5-3-3-7

With CPU Fan @12v
Idle Temps: ~38C
Load Temps: ~53C

Okay, I have some questions for some vets here. uGuru EQ is showing my load VCore at 1.34v, even though it's set to 1.45v in the BIOS. I've heard of this called the "VDroop" issue. Is this just an issue with particular motherboards or chipsets? Because I may want to trade up my AS8 to an AAXE if the 925XE boards don't have issues with "VDroop".

I have a 7700Cu that I can strap on, but I don't think that will increase my overclock to any significant degree over the AlCu.

Water cooling would probably help a lot, because I can bench SPI 1MB at 4.3GHz but Prime craps out quickly (temps were hitting 70C load at that frequency).

Everest read bandwidth was ~7600MB/s.

SuperPi (anticheat, unpatched) 1MB 32.457s

Not bad for a CPU with almost as many transistors as the old Gallatin P4EE...typically as the transistor count/cache go up, overclockability goes down. But the 90nm process counteracted that nicely.

No 3D benchies because my video cards are all PCIE at the moment.

 

[AristoV300]

Nice overclock. Droop is normal for the vcore. Some people get there boards modded to fix the issue. Sometimes a weak PSU can cause droop as well. All I want to know is where the hell everyone is getting these ES chips from

 

[jpeyton]

I'm running a 550W Fortron with dual 18A 12V rails. All the rails stay above spec under load, so I don't think that should be the problem (and I'm running almost no peripherals on this test bench). But I could always try another PSU.

I saw the mod to fix VDroop; two solder points for a 1.6Kohm resistor...I think I'll need some major practice first though.

 

[Markfw]

Questions:
1) Why is 400 mhz oc (barely over 10%) such a good OC ?
2) What are your temps ?
3) Why did you bother with an Intel CPU with todays AMD CPU's ?

 

[Duvie]

I use to experience droop with my P4 boards....This A64 board (MSI NEO2) is the first board where the vcore goes up .02 under load......The board undervolts at startup and idle versus what is set in bios, but it wont go lower then that.....

My old Epox P4 mobo drooped like .05-.06...My albatron i845pe dropped like .03-.o4....The Abit IC7 was alot like this MSI that it undervolted at startup but then it would under load drop another .02-.03v....

 

[Duvie]

By the way what prime95 test are you running....Not blended I hope....48c is good even with it being open air tested for right now....Make sure you use large FFT and get it in a case with a vid card going......check heat then....

 

[jpeyton]

Originally posted by: Markfw900
Questions:
1) Why is 400 mhz oc (barely over 10%) such a good OC ?
2) What are your temps ?
3) Why did you bother with an Intel CPU with todays AMD CPU's ?

1)People with 640s and 630s get the same overclocks...for those CPUs, it's more like a 20-30% overclock. I got a good deal on a 660, but otherwise I would have gone with a 640...much better price/performance ratio.

2)38C/53C Idle/Load with a Zalman 7700AlCu

3)I enjoy messing around with all sorts of computer hardware, meaning I have the time to enjoy Intel and AMD. In fact I have some Winnies on their way from Monarch as we speak.

 

[jpeyton]

Originally posted by: Duvie
By the way what prime95 test are you running....Not blended I hope....48c is good even with it being open air tested for right now....Make sure you use large FFT and get it in a case with a vid card going......check heat then....

Not blend 48C was on it's way to load; load is actually ~53C. With good case cooling, load temps should be around ~60C...still not bad for a Precott at 4GHz.

I have a dead A7N8X that I'll probably mess around with to get some soldering skills...HiPro has a pretty good mod write-up on the AS8 on XS.

 

[Duvie]

What is default vcore???

 

[jpeyton]

BIOS default sets it to 1.4v, which is the lowest selectable one in the BIOS. I think it's drooping between .05-.1v idle/load. I set it to 1.45v in the BIOS to get it stable.

Someone on XS mentioned measuring the VCore with a DMM to get a better idea (uGuru maybe off by a bit). I might try that if I can find the measurement points.

Also remember that these 6xx have a lot of thermal management. The EIST drops the multiplier to 14x and drops the VCore about .1v when the CPU is idle. Also TM2 can drop the multiplier and voltage if temps get exceedingly high...but you probably know all this.

 

[Sentential]

Quick question. Can you enable any of the game accelerator settings? For some reason mine hangs at post every time I try :-/ I think my board is a POS/half-dead. Just need confirmation that yours works or does not.

 

[Sentential]

Also what BIOS are you using for multiplier access? My multi adjusts are locked in the BIOS but I can change them in windows. Plus my CPUz also shows locked at 16. Which are you using?

 

[jpeyton]

Sent, I'm using the 17 BIOS that you posted on XS. The CPU is an ES, so I can adjust the multipliers using uGuru in the BIOS. The first three game accelerator settings are set to Auto, the last two are disabled.

 

[Sentential]

Ah nvm then. Must be because yours is an ES. Have you tried changing any of the "Game accelerator" settings? Mine dont work.

 

[boshuter]

Are you sure the vcore is dropping because of droop? It may just be the "speedstep" feature, if you are getting that vcore drop at idle does it come up when you put a load on the cpu? I have the 3.4 version of that cpu, also an es, when I had it on an Abit AG8 it would show 1.2-1.3 vcore at idle in UGURU but as soon as a load was applied it would come up to very close to what I had set in bios. I switched to an Asus 925x board and can disable the speedstep and thermal throttling in bios.

My cpu is prime stable at 4.0 and never gets over 47c with a Swiftech HS and 92mm fan, these things don't run nearly as hot as the 500 series prescotts. I'm doing all my benching at 4.25 so far and temps run around 50c at that speed with 1.45vcore.

 

[jpeyton]

It does fluctuate at idle because of EIST, but at load it stays at 1.34v.

 

[boshuter]

Originally posted by: jpeyton
It does fluctuate at idle because of EIST, but at load it stays at 1.34v.

Mine did run lower than bios, but not by that much. Sounds like you either need a droop mod or a different board.

 

[Capt Caveman]

IMHO, it sounds like a mobo issue. I currently am able to run my 640 @ 3.92ghz 245x16 at stock 1.4v(locked). My voltage doesn't drop below 1.4 but on occasion may rise to 1.42v.

 

[stevty2889]

My voltage droops on my Abit AS8 as well. I have my vcore set to 1.48v, but it goes down to 1.43v under load. I have a P4 550 on it, at 3.91ghz(as seen in my sig).

P.S. you are getting better temps on air than I get even with water cooling..I was hitting 72c under load, with a Thermalright XP-120..my 3.2ES never got higher than 63c with the same setup, but didn't overclock very well.