Running F2-6400CL5-2GBPQ @ 900mhz on GA-MA785G-US2H ?

[Tyrael]

hello, trying to get these 2 sticks to run @ 890+mhz on my Gigabyte 785g-us2h but i keep getting prime95 errors even with the most slack settings and 2.1v.

and when i try for 1066 @ 533 mult (1066 strap) my motherboard refuses to keep settings upon reboot out of bios, and posts @ 800mhz strap, and resets my ram to default in bios.

is there any way i can run these @ either 1066 strap 533 mult or 900mhz under 800mhz strap?

EDIT: tried upping both cpu-nb and nb voltages, 1 notch at a time each separate, then both. stopped @ 1.4 ...no need to go higher (cpu was @ 3.6Ghz and lower to test btw)

my setup

GA-MA785-US2H (f11 Bios)
Phenom II x3 740 @ 3.8+Ghz(4 cores unlocked) yes stable
2x F2-6400CL5-2GBPQ
Antec 650 TP NEW PSU

Currently running them @ 852(1:2) 5-5-5-15-24-2T

def willing to try anything considered "extreme"

[Tradesman]

Could try loosening timings to say 6-6-6-18 w/ DRAM voltage between 1.9 and 2.0, but am guessing the gain you might pick up, would be lost performance wise to the CL5 you are currently at w/ the lower speed

[GSKILL TECH]

Raising CPU-NB and DRAM Voltage should have produced better results, but if none had any affect, it may be a limited kit..

Thank you
GSKILL TECH

[Tyrael]

thanks for replies, i tried alot of settings, and it just wouldnt do anything over 880 somthing, they were not bsod(surprised) just errors in prime.

so is there no way to run these @ 1066 (5.33) ?

"limited kit"
def more like, limited board lol

[GSKILL TECH]

Should be capable, post some pictures of BIOS and I can see if anything is set incorrectly.

Thank you
GSKILL TECH

[Tyrael]

hey, ok here are the list of settings in bios (memory) no typo's

400 (800 strap)/mult allows range in settings below:
CAS# Latency (3-7)
RAS to Cas R/W Delay (3-6)
Row Precharge Time (3-6)
Minimum RAS Active Time (6-18)
1T/2T Command Timing (1-2)
TwTr Command Delay (1-3)
Trfc0 (75, 105, 127.5, 195, 327.5)
Trfc1 (75, 105, 127.5, 195, 327.5)
Trfc1 (75, 105, 127.5, 195, 327.5)
Trfc1 (75, 105, 127.5, 195, 327.5)
Write Recovery Time (3-6)
Precharge Time (2-3)
Row Cycle Time (11-26)
RAS to RAS Delay (2-5)

533 (1066 strap)/mult allows range in settings below:
CAS# Latency (3-7)
RAS to Cas R/W Delay (5-12)
Row Precharge Time (5-12)
Minimum RAS Active Time (15-30)
1T/2T Command Timing (1-2)
TwTr Command Delay (4-7)
Trfc0 (75, 105, 127.5, 195, 327.5)
Trfc1 (75, 105, 127.5, 195, 327.5)
Trfc1 (75, 105, 127.5, 195, 327.5)
Trfc1 (75, 105, 127.5, 195, 327.5)
Write Recovery Time (5-8)
Precharge Time (2-3)
Row Cycle Time (11-42)
RAS to RAS Delay (4-7)


Current Settings, not tweaked for this bus speed

400 (800 strap)/mult (4.0) 426mhz(ram bus) 1:2 divider
CAS# Latency (5)
RAS to Cas R/W Delay (5)
Row Precharge Time (5)
Minimum RAS Active Time (15)
1T/2T Command Timing (2)
TwTr Command Delay (3)
Trfc0 (127.5)
Trfc1 (127.5)
Trfc1 (127.5)
Trfc1 (127.5)
Write Recovery Time (4)
Precharge Time (3)
Row Cycle Time (24)
RAS to RAS Delay (3)



i need it to do 900mhz stable (800 strap) (225 ht bus x 4.0)
or boot windows @ 5.33 1066 strap so i can play around and all that good stuff

[GSKILL TECH]

Write Recovery Time (6)

Other than this, timings should be good to support your target. But for DDR2-1066, tWR 8 may be required.

Thank you
GSKILL TECH

[Tyrael]

from 214ht to 225ht in bios tWR 6 ram @ 900mhz instant fail
from 214ht to 225ht in bios tWR 3 ram @ 900mhz slow fail

@225ht (in bios) Maximum Read Latency gets set to 66
going from 214ht to 225ht (in software) Maximum Read Latency gets set to 71
@214ht (in bios) Maximum Read Latency appears to be set at 74

what is the relation to "Maximum Read Latency" and memory bus speed?

another change worth noting is "Read to Write Burst"(tRW-WB) gets set to 7(channel A)/7(channel B) when setting tWR to 3 in bios (happens to be 214ht in bios)

going from 214ht to 225ht via software changes tRW-WB to 7/8
setting 225ht in bios tRW-WB appears to be 8/8

so with that being said, gigabytes bios seems to be changing the hidden settings that i have no control over when overclocking, is this intended, yes.. is this good, appears not?

----1066 boot discussion-----

any advice on getting these to boot(and hold setting) @ 5.33 mult (1066 boot strap)
i think im quite limited with this motherboard, or?

[Tradesman]

The 800 sticks you have may just be at the wall right in the 800 area, that's why they make DRAM in the multitude of speeds they do i.e. 800. 900, 1000, 1066, 1100, 1200. It's interesting to try and push for that last little bit, but some sets just won't go

[Tyrael]

yea, i realize they could both be potentially lower binned 1066 that didnt make the cut @ such frequency. so ill go the tight tight timing route, and see how far i get :P or could be lack of control via bios, bios bug etc. i dont have the resources to try on other boards, brands etc.
i just kinda wanted to play around with the 1066 5.33 mult to see where i could get with cpu-nb/cpu/ram frequency.

have them temp set at 5-4-4-12-18-4tWR and they are stable, and quick, so when i get time i will def try to get the most out of them, and post back with results, right now they are pushing 8G's on maxxmem, which is not bad for 800mhz ddr2.


thanks for responses guys

[Tradesman]

Let us know how it goes