KN8 DDR500 is not quite DDR500?

[streetster]

Hey Guys,

I've just got some new OCZ PC4000 memory (2x1gb sticks), set the fsb to 200, and within memory settings set it to DDR500, and this is what cpu-z shows:




Any ideas? I tried setting my fsb @ 250, and the memory to DDR400, but the board doesnt seem to like that - ie its not stable (with the cpu @ 2250)...

[manwithnoname]

245 seems close enough - as close as you get with out overclocking.

You may have overclocked your CPU too far with a bus speed to 250
When you set the bus speed to 250 did you drop the multiplier from 11 to 9 and the mem divider from 9 to 10?
(core speed 250 x11 = 2750; mem 2750 /10 = 275 or 550DDR)
(core speed 250 x9 = 2250; mem 2250 /9 = 250 or 500DDR)

Can do a little overclock by setting the bus speed to 205 and keep the multiplier at 11 and mem divider at 9?
(core speed 205 x11 = 2255; mem 2255 /9 = ~250.6 or 501DDR)

mwnn

[streetster]

i've just rebooted with the FSB set at 250, and multiplier at 9, the memory is set at 'BY SPD' settings and is currently at 2x250.0, ie 500mhz, this was memtest86 stable for an hour (i got bored and decided to boot windows), will give prime95 a blast to make sure the board can handle it,

I've got the ram at 2.8v, and then nforce4 chipset @ 1.6, with the cpu at 1.42 just to be sure


-- edit, it died after 58minutes, what do you reckon that is? motherboard not liking 250fsb?

[manwithnoname]

Why not try core speed 225 x10 = 2250; mem 2250 /9 = 250 or 500DDR

If you have a couple of hours/days to kill you might read a overclocking guide and try lots of settings.
The gist
1) underclock your ram and cpu multiplier and keep upping the bus to find the max speed (may be up the volts on the cpu and m/b chip, and lower the HT multiplier)

2) underclock your ram and find max cpu speed

3) underclock cpu multiplier and find the max mem speed with in the max speed found from step above

4) work out some setting out within your maximums

my maximums:
fsb is 310 (Asus A8N32)
cpu is 2550 err at 1.6v (165 opty)
ram is 230 460DDR (Corsair CMX1024-3200C2 according to cpu-z)

so I decided on:
fsb is 250
cpu is 250*9 2250 at stock volts (nice and cool when cpu fully loaded)
ram is 2250/10 225 (450DDR)

So a 25% cpu overclock and 12% mem overclock without cooking my system with extra volts, not great but ok for nothing.

mwnn

[streetster]

Why not try core speed 225 x10 = 2250; mem 2250 /9 = 250 or 500DDR

thats exactly the setting i'm on now, was only prime stable for 58 minutes


I will have to spend some time working out the ins and outs of this motherboard, I was hoping (naively) that i could just whack the fsb up to 250, drop the HTT to 4, and my CPU multiplier to 9, and reap the rewards of a higher bandwidth... but that doesnt look like it's going to be the case, will have to do some experimenting this week - cheers for your input

[manwithnoname]

I wasted (err spent) lots of time trying different setting and got a bit bored with it.
Before you do anything else run prime at stock speeds for a while just incase that failure turns up without an overclock.

[streetster]

gone for a 10x230, and memory at 433 (which is cpu/10 = 230 as well), gonna play some battlefield2 and hope that it doesnt bomb out