Prescott LGA775 + 865PE... let's clock!

Hey

I recently recieved a Asus P5P800 using the "old" Intel 865PE for LGA775 Prescott's. I got a "520" (2.8GHz) and in some way I understand why Intel have a overclock limit under there 9xx chipset.

The CPU runs 250FSB at the moment (default voltage) 1:1 with a pair of Corsair PC4000 CAS3-4-4-8 and it's stable (260 or like proberly would to, but it's late now)
http://users.cybercity.dk/~dsl30381/p45201.jpg (see here - Enabling HyperPath gave 700MB/s - from 51xx to 58xx MB/s!)

At default voltage it boots at 280FSB (3,92GHz!), but not to Windows. Highest speed it boots to Windows at is 275FSB (3.85GHz), but it is'nt stable enough to complete SuperPi - I tried raising the vcore up to +100mV (1,5v), but it does'nt bring more stability in to the system.
http://users.cybercity.dk/~dsl30381/p45202.jpg (275FSB here)

unfortunately I got some memory issues. At 1:1 I can boot into Windows at 266FSB and complete SuperPi (37 seconds if anyone cares :)), 5:4 does blue screen and random reboots and 3:2 will get it booting into Windows, but I suspect the memory is not happy running 3:2 like 5:4... even if it boots in to Windows.

I got a good watercooling setup - two 80mm fans blowing over mosfets and northbridge (heatsink on the mosfets is default :D). The Powersupply is a cheap 550watt Q-tec Star VIP Gold (sounds good hehe)... maybe it's the hardware limiting me here since the CPU is using 122watt when loading at 275FSB and default voltage.

Another thing worth noting is the board does'nt recognize the CPU frequency above 3,6GHz - it's kind a random what speed it detects and in Windows CPU-Z is measureing a "unstable" FSB for some seconds (if it's set at 275MHz it will for example start measureing 266MHz for 1-2 seconds, then 272, 273 and finally 274,5...)

So.... now I wrote at roman, but check the potential of this mofo. It would might be worth trying the Abit AS8 instead wich also has the 865PE for LGA775

Yeah, the LGA775 d0 + 865PE is IMO the hot setup for Intel at the moment.

My SL7J6 (3.0e) does 3.72 (15x248 1:1 CL2-3-2-5) stable and will Post up to 4.140 (276 Mhz FSB, CL3-3-2-6) - with the stock HSF and default Vcore! Can't wait to slap the Vapo LS on. :slobber:

The Abit also supports a Vdimm up to 3.2V, which is certainly enough for my 3700EB - I've got the Booster in there anyway since it supposendly "cleans out" the voltage a bit.

BTW, did you experience any weird behaviors at high FSBs? I've heard of some P5P800 Users that had problems with FSBs over 267 Mhz - the Mobo started to throttle the Processor down to 3 Mhz once a higher FSB was selected... :confused::)

Anyway, I love my AS8. No problems at all, sweet voltages and the BIOS rocks too.

Yes - all frequencys over 3,6GHz is'nt detected correctly by the motherboard on post, but CPU-Z does. It can't be true that it kan post at 3,92GHz but only run stable at 250-260FSB no matter of vcore and underclocked memory. As I said it might be my powersupply.

Guys don't forget about the PAT hack either - if you are going to be running 1:1 look into this as you will get a nice performance boost, as if you were running 875P (and maybe even a little faster).

I haven't heard anything about that board yet but it uses the same chipset as the P4P800 so I would assume the BIOS is pretty similar.

Dont LGA755 have north chipset changes in bios?

happy member of as8 here.... 3,2@4 stable with water @ 1,56

Im also happy running 4Ghz with P4 550 (3.4GHz) and P5P800. 1.45Volts on stockcooler

Quote:

---

Originally posted by Soulburner
Guys don't forget about the PAT hack either - if you are going to be running 1:1 look into this as you will get a nice performance boost, as if you were running 875P (and maybe even a little faster).

I haven't heard anything about that board yet but it uses the same chipset as the P4P800 so I would assume the BIOS is pretty similar.

---

Now that sounds interesting. Do you have any further info on this? I can't use the search function, since it ignores all words under 4 characters (and PAT obviously has 3 :p).

hi guys.
i signed up to the forums just so i could post in this thread. :D

i've noticed some weirdness with my LGA/865PE combo.
in my case it is a P4 520 and a gigabyte 8IPE775 pro.

i've had this combo overclocked to 250fsb (using kingmax ddr500 1:1) and it seemed well enough.
until i actually put any kind of load on the cpu.

the cpu would suddenly start showing all kinds of strange speeds in various software.
usually the reported speed would drop well below the stock speed. sometimes as low as 1.4ghz.

the temps are fine. usually around the 60C mark using the stock heatsink. (surely not high enough for throttling to kick in)

after much fiddling it seems that 239fsb seems to be about the max i can go without the speed dropping under load.
quite often the speed reported on the post screen at boot up will not be correct either.

i've also noticed reported speed increases as well.
these speeds are so far out there that i have no idea what is going on.
i was running a sandra benchmark and had cpu-z open at the same time to keep an eye on the speeds.
as expected, the reported speed dropped.
but then right before the end of the benchmark it did a complete about face and i got the following results.

http://members.iinet.net.au/~dize/looktall/fastcpu.jpg

http://members.iinet.net.au/~dize/looktall/fastcpu1.jpg

those screen shots have not been altered in any way shape or form.

haha, that is an awsome overclock look tall ;)

welcome to XtremeSystems looktall :toast:

weird bugs you are getting there... doesn the system also slow down or is it just a bug about the clockspeed beeing displayed incorrectly?

i'm not sure if the system actually slows down or not.
i can't get an accurate benchmark out of it and i never bothered trying some real world apps to see how it goes. :p

I have an as8 too. I've replaced it 3 times and each motherboard starts to artifact in aquamark, parts of 3dmark and opengl games at 205 mhz 1:1 in dimm slots 1 and 3 and 115 in dimm slots 2 and 4.

I have an unlocked 3.4 EE, evga 6800 ultra, audigy 2, antec true 550, abit as8 and 2 512 meg sticks of corsair 3200xl

I've tried all sorts of timings including 3-4-4-8 and it makes no difference.

You guys think some OCZ or corsair with 3-4-4-8 default timings will fix it? My current ram is default 2-2-2-5.

'sup guys...

I'm writing this for an austrian fellow which has the same weird problems with his P5P800.

Once he pushes the FSB above a certain level, the board just goes nuts on the frequencies. CPU-Z reports ackward stuff like this :rolleyes:

The funny thing is, it's not a Clockgen thing. Setting the FSB in the BIOS produces the same results, heck, it even shows this kind of BS on the POST screen... click here

That just can't be it. BIOS updates and CMOS resets didn't help either. I've suggested to RMA the board, but since looktall has similar problems it's probably a general P5P800 problem and/or incompatibility rather than a faulty component on his specific board.

as a sidenote, im having a blast with my AS8 even though the vcore likes to drop up to 0.1V under load (nah, it's not the PSU... the system is powered by a 520W OCZ, the 3.3/5/12 rails are perfectly stable).

http://www.moep.at/screenshots/cpuz.png

I have to admit that this screenshot was done kamikaze style - not stable at all... still Aircooled due to the lack of a Vapochill LS 775 Socket-Kit, i'm hoping for 4.2 Ghz stable with the LS, maybe even more. :banana:

Very nice result from that lga775 3.0E on air moep. Whats the stable speed you can get out of it?

Im going to get a P5P800 or a AS8 to try out with a lga775 2.8 probably. I'l half to use air cooling untill I get a Mach II GT :grin: It should be intresting to see what the results are.

Quote:

---

Originally Posted by moep

'sup guys...

I'm writing this for an austrian fellow which has the same weird problems with his P5P800.

Once he pushes the FSB above a certain level, the board just goes nuts on the frequencies. CPU-Z reports ackward stuff like this :rolleyes:

The funny thing is, it's not a Clockgen thing. Setting the FSB in the BIOS produces the same results, heck, it even shows this kind of BS on the POST screen... click here

That just can't be it. BIOS updates and CMOS resets didn't help either. I've suggested to RMA the board, but since looktall has similar problems it's probably a general P5P800 problem and/or incompatibility rather than a faulty component on his specific board.

as a sidenote, im having a blast with my AS8 even though the vcore likes to drop up to 0.1V under load (nah, it's not the PSU... the system is powered by a 520W OCZ, the 3.3/5/12 rails are perfectly stable).


I have to admit that this screenshot was done kamikaze style - not stable at all... still Aircooled due to the lack of a Vapochill LS 775 Socket-Kit, i'm hoping for 4.2 Ghz stable with the LS, maybe even more. :banana:

---

i think you need the latest service pack for xp or server 2003 to get rid of that bug. it has to do with the way the os recognizes the clockspeed of the cpu if im not mistaken.

Quote:

---

Originally Posted by Bennah

Very nice result from that lga775 3.0E on air moep. Whats the stable speed you can get out of it?

Im going to get a P5P800 or a AS8 to try out with a lga775 2.8 probably. I'l half to use air cooling untill I get a Mach II GT :grin: It should be intresting to see what the results are.

---

it's running at 262x15 stable, cant complain about it.
The RAM is 3700EB 1:1 (3-2-3-8 with 3.2V), which is pretty neat as well. The screenshot was taken w/ 1:1 as well, with the same timings. :)

I'd seriously consider the AS8 instead of the Asus though. One major advantage is the ability to run PAT high FSBs (actually, my AS8 allows PAT at up to 256 Mhz FSB) whereas the Asus disables PAT as soon as you pass 200 Mhz FSB. If you get a lucky board and/or do a Vagp mod, i guess you could run up to 270 Mhz FSB with PAT enabled... :slobber:

BTW, saaya, i don't think it's a software problem... the weird frequencies show up in the BIOS as well.

//edit: d'oh, i just noticed that i linked the wrong pics in the posting above. I've updated the links, please check em out one more time. :yawn:

Hey

Anyone tried the Soltek SL-865PRO-775 ... I can't deside between that and A8s... So if u have any expirience with the soltek board, it would be great... :)

ZyRiX

Quote:

---

Originally Posted by Unseen

happy member of as8 here.... 3,2@4 stable with water @ 1,56

---

How you mount the block on the AS8? It has 2 capacitors (up and right) around the socket that are higher (is taller the word?) than the core surface.

I tried to mount my Cascade waterblock but due to it's size it does not make good contact with the cpu core.

Perhaps removing those capacitors and soldering them at the back of the board?

Regards.

custom waterblock ;)

P5P+560 Stock cooling and vcore default ;) PAT Disable :(
http://www.ocpassion.com/CarNabY/Asus775/Screen11.GIF
http://www.ocpassion.com/CarNabY/Asus775/Screen04.GIF
The voltage in cpuz not real..bug

P5P+560 Stock cooling and vcore +0.050v
http://www.ocpassion.com/CarNabY/Asus775/Screen05.GIF
http://www.ocpassion.com/CarNabY/Asus775/Screen10.GIF
Maybe with BH5 2-5-2-2 30 sec? Mmmmm :rolleyes: Water cooling? :)

is AGP and PCI lock working on the board and anyone know what the top FSB on the board is?

Quote:

---

Originally Posted by CarNabY

P5P+560 Stock cooling and vcore default ;) PAT Disable :(
http://www.ocpassion.com/CarNabY/Asus775/Screen11.GIF
http://www.ocpassion.com/CarNabY/Asus775/Screen04.GIF
The voltage in cpuz not real..bug

P5P+560 Stock cooling and vcore +0.050v
http://www.ocpassion.com/CarNabY/Asus775/Screen05.GIF
http://www.ocpassion.com/CarNabY/Asus775/Screen10.GIF
Maybe with BH5 2-5-2-2 30 sec? Mmmmm :rolleyes: Water cooling? :)

---

Very nice results :)

Maybe using BH-5 2-2-2-5 may bring you down into the 30sec mark ;)

Quote:

---

Originally Posted by Bennah

Very nice results :)

Maybe using BH-5 2-2-2-5 may bring you down into the 30sec mark ;)

---

Maybe :)
Tomorrow I have two modules of BH5..Mushkin 3500 2x256Mb..
I need vmem mod...2.85v they are not enough for 235 2-5-2-2 :(
I have here oczbooster...but I cannot use it with the P5P800 :mad:

How come you cant use the booster?