2400 htt bus ...is it safe?
After reading some of lemonlimes oc manual I'm beginning to wonder if this is safe or not ...or even if I did the math correctly.
This is what I have:
cpu frequency [240]
processor frequency multiplier [x11]
memclock value [200 mhz]
ht link speed [1000 mhz]
240x5x2=2400
Not really sure what 1000mhz ht link speed is yet...
Not even sure how to change the LDT multi ...
At any rate this is what I got to last night and it's been folding at this ever since. Let me know please.
Thanks
csimon
This is what I have:
cpu frequency [240]
processor frequency multiplier [x11]
memclock value [200 mhz]
ht link speed [1000 mhz]
240x5x2=2400
Not really sure what 1000mhz ht link speed is yet...
Not even sure how to change the LDT multi ...
At any rate this is what I got to last night and it's been folding at this ever since. Let me know please.
Thanks
csimon
0
Comments
I don't really think it is 'dangerous' or 'unsafe' to run a high HTT frequency, but generally speaking, you'll obtain the highest level of stability at close to stock frequencies. My recommendation would be to use the 4x LDT multiplier (which will give you about 1920MHz). 1920MHz should be perfect at that clock, as its very close to stock. If you are 100% stable at a 2400MHz HTT, then there is really no harm in keeping it there.
Definitely try the 4x multiplier (probably 1600MHz link speed in your BIOS settings) if you want to push further on your CPU clock. Your high HTT bus frequency could be holding you back. It appears that your mainboard does not actually specify 'LDT multiplier' or 'HTT multiplier' in the BIOS. I believe that link speed is actually the LDT multiplier.
5x=2000MHz
4x=1600MHz
3x=1200MHz
You did do the math correctly btw. The maximum HTT speed you can achieve does vary from platform to platform, and the ATI based boards seem to handle very high HTT bus frequcies much better than the nforce4/3 systems. I've heard rumors that the 580 based boards really excel in this arena. It matters very little though, the HTT bus is simply not a bottleneck, even at the default frequency of 2000MHz.
My DFI NF4 for example, does about 2450-2500MHz before I start getting strange no-posts and hard locks.
Yes it's unusually stable at 1000mhz ht link speed but it feels like I get more bandwidth from the cpu/controller the lower I go.
So do they usually have that many multi's 5-1?
Oops, yeah, so it should equate to:
1000MHz = 5x
800MHz = 4x
600MHz = 3x
400MHz = 2x
200MHz = 1x
HTT bus is 'double data rate' so you can multiply that by 2 to obtain AMD's specified 2000MHz at 5x.
That is interesting that you found your system most stable at a 2x LDT multiplier. I have yet to be able to maintain stability using that LDT multiplier with anything lower than about 350MHz of reference clock. Usually the 4x and 3x multipliers are the most widely used.
Generally, there should be little to no performance change whatsoever when changing your HTT frequency (especially strange that your performance improved when decreasing it). Perhaps there was some other factor at play?
At any rate just for sh*ts & giggles I'm thinking about trying 2.5cl at this ht ...I changed to 3.0cl at around 235 when I started getting freezes but that was remedied by a bump to the vcore.
Can you recommend a good inexpensive UPS?
If you plan to increase your reference clock any further, I'd definitely look at reducing the LDT multiplier (try the 800MHz setting). That is probably the main thing holding your overclock back right now, as the board is teetering on the edge there. Once you set the 800MHz LDT multi, you should have tons of headroom before HTT will become an issue again.
Have you tried to put the memory on the 5/6 or 2/3 divider just to see how high you can get your CPU clock with memory out of the picture?
Hey Chris, just noticed that you mentioned Cn'Q earlier. Do you have this enabled and working? That could definitely affect your overclocking potential. I'd strongly recommend disabling this.
Cn'Q will reduce your CPU multi and CPU voltage, but since you are increasing the reference clock, it may not be stable once the chip drops everything.
I.e 800MHz @ >default vcore may be stable with a 200MHz default reference clock, but if you increased your reference clock to 240MHz, Cn'Q will basically drop everything the multiplier down, but you'll be at 960MHz @ >default vcore because of the reference clock, and instability may occur.