LGA775 at 4 gig

[batboy]

Well, was reading on another forum about how some of the i915/i925 chipset boys were having to use NB voltages of up to 1.8v to get extreme overclocks (1.5v is default). I had used 1.6v and never noticed any difference (was nervous about raising the voltage any more on a brand new system). Decided to try 1.8v NB today plus 1.51v vcore too. Now keep in mind that I've never even been able to post above 246 FSB before and even that wasn't stable enough to run CPU-Z (green system in signature).

I ran Sandra CPU and Sandra memory bandwidth before my temp alarm went off (I have it set at 65 degrees). This TT Jungle is sort of wimpy. Got a brand new XP-120 sitting right here still in the box though... hmmmm. If I'm going to start cranking high NB volts, I might see what I can do about better cooling there too. Anyone else with a LGA775 system tried running higher NB voltage yet? Please post your results.

 

[Jimbob7]

Thats good to know. Has it given you a higher stable overclock? Or Just let you boot into windows higher?

 

[Maxvla]

excellent results batty.

 

[@md0Cer]

Nice work batboy!

Another 4GHz Prescott on air cooling!

This also adds more proof for me to show that you can get a decent overclock with a Prescott on air cooling to those diehard AMD fans who insist you need thermal cryotechnics to run it even at stock speed.

 

[Maxvla]

This also adds more proof for me to show that you can get a decent overclock with a Prescott on air cooling to those diehard AMD fans who insist you need thermal cryotechnics to run it even at stock speed.

no prommie no care

 

[batboy]

Sorry I haven't posted back lately. I had my rig tore down last night trying to improve cooling. To answer Jimbob, I don't know yet if I'm 100% stable at 4 gig until I take care of my cooling issues. It's looking promising though.

I'm having trouble fitting my new XP-120 heatsink. The N/B cooler on these Abit AG8/AA8 mobos sit up too high. Tonight I will try one of two things. See if my old trusty Thermalright SLK-947 will fit on this LGA775 adapter or try to fit my extra Zalman chipset heatsink onto the board.

I also installed a heatsink on the PLL chip and think I might sink up the mosfets. Looks like there are 16 main mosfets on the power circuitry... that's twice as many that my IC7 had.

 

[sevendevilhell]

have you seen fugger's record?

6.3 GHz with an i875P and a 3.6G LGA775 cpu. and this is no lie: he was stable enough to boot up, take CPU-Z screenshots, and post them on various forums.

(this is with triple phase change cooling, so i'm quite impressed with what you've gotten on wimpy air cooling)

 

[Achilles17]

Isnt the XP-120 suppossed to cover the NB, so that you dont need seperate NB cooling? I thought it was suppossed to blow air on both, so just try and cut a heatsink yourself so it can fit, and have the 120mm fan from the xp-120 blowing on it. or dont even make a sink, up to you. BTW, when you say NB voltages, do you mean the AGP voltage? Cuz that does run through the NB. Or on 775 boards is there a seperate NB voltage controller in the bios? Also, do you know if this might work on a northwood? looking to up my northwood from 4ghz stable

 

[batboy]

Achilles, the XP-120 does hang over the N/B cooler a little. The LGA775 mobos are indeed designed to have the CPU fan blow air onto the mosfets, RAM, vid card, and N/B heatsink. The Abit AG8/AA8 mobos have a unique N/B cooler. The fan sits up vertically and blows air across from the CPU towards the vid card (see pic).

The XP-120 hits the clear plastic fan on the N/B cooler. Now, I could just take the fan off and that would probably work since like you indicated, the air blowing from the 120mm fan on the XP-120 would definitely blow across the N/B heatsink. But this will be warm air after passing through the XP-120 fins.

Running without a N/B sink is not an option. Since I'm raising voltage, I want to improve N/B cooling, not make it worse. Yes, I can cut down a heatsink if needed. My Zalman heatsink dropped temps a lot on my IC7 combined with a high output Sunon 40mm fan, so I'm going to try that first since I have it handy.

The i915/i925 chipsets don't have AGP slots (PCI-E slot instead), so there is no AGP voltage. This mobo has a separate N/B voltage setting in the BIOS. Adding extra voltage to the N/B has been done with Northwoods. There is a AGP volt mod for the Abit IC7 mobo, so I guess there might be one for Asus too.

 

[jenko]

How about spinning the NB cooler 180degree`s? and if there still isnt enough room cut down the 1st set of fins?

 

[DanIdentity]

Awesome batboy - what are your temps at 4 gig?

You might want to try an XP-90 if you can't get the XP-120 to fit. It uses the same LGA775 adapter and the cooling is almost as good.

 

[Achilles17]

Yeah, there is an AGP volt mod for the p4c800-e, but i never did it. The AGP can go up to 1.7v or 1.8v in the bios, so that would probably be enough. This would increase my NB voltage, correct? Also, is there any chance it could fry my graphics card, or is the card pretty safe as long as the core stays at 1.4 or 1.5v? Right now I believe I have the AGP at 1.6v (1.5v stock), but if i could bump it up without severly hurting things, it might be worth it. My NB already gets kinda hot tho, even with the Microcool Northpole on it. It gets up to around 45C load according to my temp sensor, which is a little bit away from it.

 

[musawi]

Yeah you deserve 4 ghz more than anyone I know.

 

[batboy]

How about spinning the NB cooler 180degree`s? and if there still isnt enough room cut down the 1st set of fins?

Yes, rotating the N/B cooler would indeed work and I thought about doing that, but I figured the fan blowing toward the CPU would be fighting against the CPU fan blowing away. OMG... I just thought of something while I was typing this. What about rotating the N/B heatsink 180 degrees and then flipping the fan around so it's pulling air from the sink instead of blowing through the sink. Brilliant! Then the flow is still going the right direction. Yippee! I'll do it because it looks like the Zalman sink with fan will still be too tall.

Awesome batboy - what are your temps at 4 gig?

You might want to try an XP-90 if you can't get the XP-120 to fit. It uses the same LGA775 adapter and the cooling is almost as good.

Dan, I haven't checked temps yet. With my Jungle heatsink, it got too hot and set my temp alarm off, so I immediately shut it down. I started working on improving cooling and got stuck with the clearance issues of the XP-120 heatsink. I hope to have it all back together tonight. I'll report back with temps.

Yeah, there is an AGP volt mod for the p4c800-e, but i never did it. The AGP can go up to 1.7v or 1.8v in the bios, so that would probably be enough. This would increase my NB voltage, correct? Also, is there any chance it could fry my graphics card, or is the card pretty safe as long as the core stays at 1.4 or 1.5v? Right now I believe I have the AGP at 1.6v (1.5v stock), but if i could bump it up without severly hurting things, it might be worth it. My NB already gets kinda hot tho, even with the Microcool Northpole on it. It gets up to around 45C load according to my temp sensor, which is a little bit away from it.

Yes, you are correct, increasing AGP voltage does increase N/B voltage (at least on most i865/i875 chipset mobos). I run 1.6v all the time on my IC7 mobos and 1.65v some of the time. That's as high as the IC7 will go without modding them. How safe is higher AGP voltage to vid cards? I don't know.

 

[man_utd]

Wow, have you tried running with a box fan blowing in, just for a quick test of how far your air will take you? Never hurts

 

[batboy]

Wow, have you tried running with a box fan blowing in, just for a quick test of how far your air will take you? Never hurts

Wish I'd thought of that house fan idea yesterday before I took everything apart.

 

[man_utd]

Heh, hindsight is 20/20, but good luck with your new setup.

 

[beau_zo_brehm]

nice clocks batboy! on my system i have the side of the case opposite of the motherboard taken off so i have an industrial fan blowing on it. It lowered my temperatures by about 12 C, and I have the same cpu and motherboard as you do. Do you plan on eventually wc this system? I had problems with my waterblocks touching capacitators on this new technology, so i have to wait until i can find suitable waterblocks.

edit: actually i have the aa8 motherboard, but i didnt even notice looking at the picture because they are basically the same architecture.... do u know any mods for these motherboards?

 

[beau_zo_brehm]

damnit batboy... 4 ghz is really elusive on air

 

[batboy]

Well, it's close... but not quite stable at 4 gig. I can run most benchmarks, but PCmark2004 won't complete.

Load CPU temps at 4 gig and 1.51v is 60 degrees. The system temp is a few degrees higher than before, but that's because I'm putting 1.8v through the N/B at 4 gig (default is 1.5v). PWM1 and PWM2 temps are lower by a few degrees.

Rotating the N/B cooler 180 degrees and flipping the fan worked. The XP-120 fits now.