perf lvl 4 500mhz 4-4-4 2.2v! but how?

[RAMMAN]

performance_level_4.bmp (1.6 MB)

when i set 4-4-4-12 and 2:3 divider in bios my board automatically defaults to performance level 4 and its 24/7 stable, i can even play tf2 with it for hours. yet if i attempt to set performance level 4 with memset at a different divider, instant bluescreen regardless of other settings. can anyone explain it?

edit: it scaled to 1066 same voltage, timings except performance level 6. i havent attempted to raise the fsb while still keeping performance level 4. changing performance level from 4 to 6 results in lower read speed and higher latency.

[zanzabar]

fsb makes more of a difference i have gotten ddr2 down to 3-2-2-7 with 400mhz and 400mhz fsb and it was the same as yours (u have better clock for clock ram speed with the p35 v my old dfi x38 LT)


but with cas4 pl6 500mhz ram and fsb its a huge amount higher


then 5-5-5-15 pl8 or 7 with 500fsb 600mhz ram and it smokes

[RAMMAN]

yeah, i have a crappy board thats incapable of much past 400fsb with quads, but im more interested in how my memory is stable with performance level 4, can someone explain it and for that matter can anyone else run perf lvl 4 stable? maybe its the combination of my memory (gkx i think) and the p35 chipset?

edit: perf lvl 6 400fsb 4:5 only slightly better than perf lvl 4 333fsb 2:3 everest latency wise, both 500mhz 2.2v

edit2: i have to use 2:3 divider as its the only way to push past 500mhz memory clocks with this board

edit3: 1200 5-5-5-15 2:3 400fsb 2.2v perf lvl 6 resulted in bluescreen, 1170 is stable though.probably has something to do with perf lvl being to tight and voltage way too low for these clocks.

[RAMMAN]

heres some results at 370 and 400fsb respectively(the limit for my crappy mobo) both results at ddr2 2.3v mch +0.1v 2:3.

1110 4-4-4-12 pl7, badwidth and latency numbers not so good and not stable, could have tried tighter pl but it was unstable as it was and had to save the result and reboot quickly before bluescreen

1110_4-4-4_2_3v.bmp (766 KB)

1200 5-5-5-15 pl6, much better bandwidth and latency

1200_5-5-5_pl6.bmp (771 KB)

not bad for 400fsb and relatively low voltage, and i still havent tried 5:8 ratio which i will need if im to attempt to get near the rated speed for my memory on this board.

edit: i get the feeling attempting 1200 4-4-4 isnt worth the trouble and will require too much volts only to get lower everest bandwidth numbers anyway

[RAMMAN]

1280 5-5-5-15 pl6 400fsb 2.35 vdimm +0.1fsb +0.1 mch 5:8

1280_5-5-5_2_35v.bmp (774 KB)

tried memtest instant errors, i was quick to shutdown before it could bluescreen.earlier i tried 406fsb pl7 and it locked up, in hindsight it was definitaly the memory as it was already unstable at 400fsb.anyway thats as far as i will go until i get a gigabyte p45 ud3 series board, as 400fsb is really holding this ram back, im getting only slight improvements in read, copy and latency, no change in write going from 1200 to 1280 same timings same pl same 400fsb.

edit: turns out i can get even higher bandwidth and lower latency at 1200 5-5-5-15 pl5 400fsb 2.3 vdimm +0.1 mch 2:3

1200_5-5-5_pl5.bmp (768 KB)

and that result was stable unlike some of the others.

i also attempted pl4 but it bluescreened around 1100

[xdrift0rx]

I'm a little new to this "performance level" aspect for ram. just picked up a dfi p35 for cheap and have never seen so many options for ram...

so with lower latencies you use a lower performance level and with higher lats you raise the performance level?

[WaterFlex]

hehe guys, my old good CellShock "Red Devil" used to do a much more great work

[Reefa_Madness]

I'm a little new to this "performance level" aspect for ram. just picked up a dfi p35 for cheap and have never seen so many options for ram...

so with lower latencies you use a lower performance level and with higher lats you raise the performance level?

Here a little article that you might find of interest.

http://www.anandtech.com/cpuchipsets...spx?i=3184&p=8

[WrigleyVillain]

This one too (starting on like page 5):

http://www.anandtech.com/mb/showdoc.aspx?i=3208

[RAMMAN]

the other day i put +0.2v through the mch on my old ga-p35-ds3p. within 60 seconds the mch seemed to have degraded , it tried to reboot to 1000 4-4-4-12 pl4 2:3 and couldnt, after a few seconds it booted by itself at 800 5-5-5-18 pl6 5:6 just fine. if i tried raising the fsb around 388-390 it would lock up and display a weird error while still in windows, something about the memory being unable to read or write to somewhere i cant remember.doesnt make sense, p35 chipset should be able to handle mch +0.2v, i have even seen some memory representatives recommend mch +0.2v for that particular board. only reasonable explanation is the northbridge getting insanely hot.since then i have moved on to a new mobo(see sig) and being more careful with voltages except dram, so dont expect any amazing clocks from my team xtreem 1300s before the end of the year.

edit: on 2 occasions the heatsink has came off one of the sticks in similar fashion to what happened to the op in the following thread:

http://www.xtremesystems.org/forums/...highlight=duck

has me worried, as the op ended up with dead ram in just over a month