matched or unmatched ram

[surajspai]

hello,
my config is as follows
gigabyte 785gm-us2h mobo
amd a2 x4 630 2.8ghz
corsair vx 450 psu
no gpu
i was looking to boost my aging pc and wanted to get a ram upgrade.
locally,i can buy these kits
gskill f2-6400cl5s-2gbpq(a total of 2 kit for 4gb)
or
i have to get this kit,from abroad
f2-8000 cl5d 4gbpq

now,my question is will any of these two kits have compatibility issues with my mobo?
also,if i purchase the 6400 kit,i will get a local dealer warranty(he will rma it for me),so,no rma issue.
if i get the 8000 kit,i have to send it to taiwan myself(in case of rma)that costs a bit from where i stay,and customs is a real pain.
so,i would prefer the 6400 kit,because i dont intend to use this pc for more than 1-1.5 years.but,i want the pc to run trouble free,without any issues.so,which kit do i purchase?the 8000 or 2x2gbpq 6400 kit?what about issues with the 2gbpq in dual channel mode?

[GSKILL TECH]

Just go with the 6400 kit, as long as the vendor can assist with any issues.

Thank you
GSKILL TECH

[surajspai]

i shall do that.thanks a lot!

[surajspai]

it seems my dealer can try to get the 8000 4gbpqkit.so,any compatibility issues with my board-gigabyte785gm-us2h?i would like the extra mhz for overclocking headroom and its a matched kit too?
please reply
thanks and regards

[Tradesman]

Shouldn't be a problem, and 2 sticks instead of 4 will be easier on the AMD MC. Also can always drop the speed and tighten the timings for a possible boost

[surajspai]

hello,
i tried out my gskill 8000 cl5d 4gbpq kit on a intel rig,pushed the rams to 1080mhz,stable(i didnt push them further as my proccy had poor cooling,overclocking it was a risk).
havent tried them on my amd pc,and,i thought,i will run them at 1066 on my amd rig.
so,if i input the settings according to this guide,
http://www.gskill.us/forum/showthread.php?t=4790
will it be ok?
my rams are 8000 PQ's,and wondered if the settings for the 8500 PK's would be fine?

[Tradesman]

The PQ 8000s are rated at 5-5-5-15, so if trying to push them to 1066 the timings of the 8500s (5-6-6-18) should probably work if you get them there. May have to tweak voltages a little for the OC

[surajspai]

i tried to do 1066,
these settings from the 785gmus2h guide for 8500pk

DRAM Configuration (submenu)
DDRII Timing - Manual
CAS Latency - 5T
RAS to CAS R/W Delay - 5T
Row Precharge Time - 5T
Minimum RAS Active Time - 15T
1T/2T Command Timing - 2T
Trfc0 for DIMM1 - 127.5ns
Trfc2 for DIMM2 - 127.5ns
Trfc1 for DIMM3 - 127.5ns
Trfc3 for DIMM4 - 127.5ns
Write Recovery Time - 6T

System Voltage Control - Manual
Set Memory Clock - Manual
Memory Clock - 1066
DDR2 Voltage Control - +0.3V
Northbridge Voltage Control - +0.1V

when i input these settings,the rams default back to 800.

when i put 5-6-6-18 1066mhz,the system dosent get past the bios screen,so,i shutdown and remove the bios battery,reset the thing,boot back again.

i tried 4-4-4-12 @800mhz,ddr2 voltage 2.1,north bridge voltage+0.1,the system boots,but is not stable,gives bsod,after sometime.
these did 1080mhz on a asus P5QE,stable at 5-5-5-15,2.1v
but,i am not able to replicate these results on my amd system.where am i going wrong?
is it compulsory to overclock these by raising my fsb(or htt?)
also,my mobo is 785GM-US2H,rev 1.0,bios F5(latest f12)
please help

[Tradesman]

May have to settle for 1000 at stock settings, your CPU may not be able to push 1066, not positive about your model but many AMD CPUs have trouble at 1066 or higher.....could try a little more voltage to the CPU

[surajspai]

tried it out on the intel system myself,to do 1066 or 1080 mhz(5-5-5-15),i need to up the voltage to 2.2v.my amd mobo limits me to just 2.1.so,i guess thats what holding me back?
anything else that i can try?

[Tradesman]

Have you tried w/ a little more voltage to cpu and or NB? or dropping the speed to 1000

[surajspai]

let me try.i have undervolted my cpu to 1.325v.nb is at +0.1.how much do i increase it by?

[Tradesman]

Try +0.1 to NB and take CPU to 1.35, if no joy can try a little higher

[surajspai]

no use.it still reverts back to 800 mhz.such nice rams on a good-for-nothing board.
by the way,i see that there is a "cpu nb vid".would tweaking that help me to get 1066?

also,while im still running at 800mhz?are there any lower ram timings i could try?

[Tradesman]

Yes, you can add a little more juice to it, may .05 to .1, or try at 6-6-6-18, another possible is at tated speed w/base timings.........if at 800 now could tighten the timings for a performance boost