phenom 555 unlocking issue?

[thingemajib]

gotta new phenom 555, and sucessfully unlocked a stable quad (p95 for 2hrs).

The only bios foxconn does for my board that "supports" core unlocking (not ACC - all Fox bios have that) is the p03, which is the very first release.

My problem is that, i can only boot with the HT multi less that 5x (1000mhz), anything higher than that, and i get a blank screen untill i reset cmos. not tried overclocking anything yet, but i have thrown a fair few volts at both cpu and HT-sb link with no sucess

i have no idea if this is due to a possibly dodgy BIOS or a possibly dodgy 3rd/4th core

any ideas?

 

[Uriel]

Try bumping up CPU-NB voltage gradually. Also consider NB-Core and NB-PCI-E voltages. vCORE may help. Drop RAM speed as far as you can and use manual timings at the slackest recommended by the manufacturer. You can gradually shift it back up later if you get the CPU stable. Don't let your overall NB speed get too low. Try to keep it between 1800 MHz and 2100MHz (you'll need to drop the multi as the CPU clocks higher).

After unlocking my X2 5000+ 45nm I found that generally bumping up vCore helped if I was getting Prime errors or freezes. For BSODs (especially while booting Windows), vCPU-NB was a good place to start.

I have a dodgy core on my unlocked CPU. I can get it Prime (and anything else I throw at it) stable but I get Machine Check warnings in Windows Event Viewer. As long as these are only warnings not full blown errors the machine will be usable (although if you're doing any really important work I'd consider turning ACC off for added stability guarentee).

 

[thingemajib]

the cpu seems stable at stock speeds, its just the HT thats playing up. If i left it, how much of a bottleneck would 1000mhz HT be to a quad?

ive not had any crashes or error reports, just the noot booting thing if i go over 5x multi :S

 

[thingemajib]

ok,

went back to p03 bios (using as dual for the moment ... 3.96Ghz @ 1.4v if anyones interested...), set following:

ACC auto
CnQ off
c1e off
spread spectrum off
Ht at 5x
ram down to 800mhz,
cpu +125mv, or just off 1.5v (naf bios only tell me increments, not actual voltage)
nb +180mv, or 1.48v
Ht-sb +180mv

this makes it better...er, i can get to 8x multi, before it wont boot. ive dropped the cpu vcore back down, and it still boots, so its not that. Im still testing and tweaking, but i though itd put some progess on here to see if any other suggestions crop up.

how far should i be going with northbridge/HT voltage? Im concerned about possibly frazzling something

mobo cooling setup:
http://www.foxconnchannel.com/Upload/Mainboard/200903110837140490_A7DA-S 3.0_left.jpg

atm, northbridge is idling at 44.c and southbridge is idling at 34.c

 

[Meaker]

Good news, HT has 0 performance impact, certainly over 1Ghz.

 

[thingemajib]

even for a quad at 3.8-4ghz?

and ive discovered that i can still overclock it through the base clock (or whatever it is)
but the wierd thing is that, i can put the multi back upto 10x in AMD overdrive withour any issue (not at home, so no screenie, but it was 2400mhz last time i was on it). CPU-z comfirms as well

cant find any benchmarks that specifically target HT. any suggestions?

 

[Meaker]

Yeah, its mostly used to interconnect CPUs in multi processor socket systems.

 

[Uriel]

IIRC it affects GPUs in SLI / Crossfire too.

 

[Meaker]

I don't see why it would, I could be wrong though, do you have a link?

 

[Uriel]

http://techreport.com/articles.x/14261

Not quite what you're after but HT affects the link between the GPUs and system RAM. I would have thought the performance improvement will come when there's more video data to cope with than you have on your graphics card so the GPU starts using system RAM. In general use that's very rarely a bottleneck. There aren't many games that use over 512MB video memory. I don't think there are any that exceed 1GB yet.