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i5 overclock - limited by my DDR1600 G.Skill?

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SunTzu69

Member
Joined
Apr 30, 2004
Location
Canada
[RESOLVED]

Dear friends,

I followed Miahallen's suggestions as referred to in this thread:

http://www.overclockers.com/forums/showthread.php?t=630823&highlight=settings

I run the GA-P55-UD3R motherboard (F4 bios) with an i5, and this G.Skill ram:

http://www.newegg.ca/Product/Produc...193&cm_re=g.skill_1600-_-20-231-193-_-Product

I believe I am being limited by my ram, as I did not run into problems at the Bclock level at all up to 190 Mhz and on stability test. However, I have trouble getting to 162 Mhz using 9-9-9-24, vtt 1.35v, vcore 1.3v, vdimm 1.66v. At 160 Mhz I am fine, beyond that I get errors right on boot up. My temps seem alright in HWmonitor and Speedfan. I am sitting at around 57c per core under Prime95.

Do you guys have any suggestions? This cpu has to have more than 3.4Ghz in store for my new build, or at least I hope. Other information:

Earthwatts 650w
Megahalem Mega Shadow Deluxe push/pull 1200 rpm

I have run DIY watercooling on two setups in the past, but it's been a while since I have attempted an overclock. The bios is much more complex than what I am used to playing around with.

I am not very comfortable with surpassing vtt 1.35v as Miahallen suggests. Should I really push further? I want a 24/7 setup and can live with a few 100 mhz less if it means a more stable/reliable system down the road. I'm just disapointed most people seem to be in the 3.6-4.2Ghz range.

I am stuck at 21x160. Not my proudest moment in OC. :shrug:

Edit: I am reading the first post I link for the third time and realize I could use a x8 ram multi. Would that result in any diminishing returns? Is it worth it to push to 4.0?

Thank you
 
Last edited:

Brutal-Force

Member
Joined
Feb 22, 2009
Hrm... at 162 Bclk, your Ram shouldn't be limiting you yet IF you have it in Dual Channel Interleaved Mode. (1 stick in each odd bank or 1 in each even bank) Same colored slots.

You should be able to achieve 400MHz Ram speed for a 1600 Ram Clock speed.

8X multi should work until you hit 200 Bclk. If After 200 lower it to a X6 Multi.

As for the 1.35V QPI/Vtt, you shouldn't need more than that.

Have you tried exactly like Miahallen said to do it? Do your Bclk first. After that your RAM, and then start on your OC.

Can you only get 162 Bclk if you turn your Multi down to about 10? If not, its something else besides your CPU. Your RAM shouldn't be causing your issues.

Note: 1.3V Vcore is low for anything less than 3.8GHz AND You need to have all power saving functions disabled. Try 19X190 and see if that works, if not, back down to 18X190 and so on till you find a stable OC. Sounds to me like you went straight for the 4.0 with out finding out what each component is capable of.
 
OP
SunTzu69

SunTzu69

Member
Joined
Apr 30, 2004
Location
Canada
Hrm... at 162 Bclk, your Ram shouldn't be limiting you yet IF you have it in Dual Channel Interleaved Mode. (1 stick in each odd bank or 1 in each even bank) Same colored slots.

You should be able to achieve 400MHz Ram speed for a 1600 Ram Clock speed.

8X multi should work until you hit 200 Bclk. If After 200 lower it to a X6 Multi.

As for the 1.35V QPI/Vtt, you shouldn't need more than that.

Have you tried exactly like Miahallen said to do it? Do your Bclk first. After that your RAM, and then start on your OC.

Can you only get 162 Bclk if you turn your Multi down to about 10? If not, its something else besides your CPU. Your RAM shouldn't be causing your issues.

Note: 1.3V Vcore is low for anything less than 3.8GHz AND You need to have all power saving functions disabled. Try 19X190 and see if that works, if not, back down to 18X190 and so on till you find a stable OC. Sounds to me like you went straight for the 4.0 with out finding out what each component is capable of.

Thank you for the response. I figure you meant "for anything more than 3.8Ghz"?

I do have the RAM in the correct slots. I feel it's something I am missing in the BIOS or my understanding of the RAM multi. All of my testing (other than the Bclock headroom) has been using the 10x RAM multi (as opposed to the 6x or 8x). Is that where I am completely offside? 200mhz x 8 = 1600? That may be where I was misunderstanding things, is 8x a 1:1 memory/cpu ratio with no performance loss?
 

Brutal-Force

Member
Joined
Feb 22, 2009
Yes, more or less. You would be limited by your ram id you were trying to achieve higher than 200 bclk with ram set at 8 or higher. While having ram set higher would give you higher ram speeds at 1:1, what good would it do if your OC was limited to 3.4GHz. You have to find the happy medium.

Lower your ram multi at the same clockspeed. Do a Ram benchmark before and after. You will get the idea.
 
OP
SunTzu69

SunTzu69

Member
Joined
Apr 30, 2004
Location
Canada
Thanks for taking the time :)

I am running all Prime95 tests stable (only 5 min tests for now), including the blend at 181x21. My cpu is running fine at 3.8 Ghz, temps under 60c under prime loads.

I would like to confirm that the following Memory settings are good for running this as a 24/7 system without hampering my memory performance:

DRAM Frequency 724Mhz
FSB to DRAM 2:8
9-9-9-24
tRFC 80 clocks
CR at 2T

Is that how it's done? For some reason I thought a 2:10 FSB to DRAM was what I was aiming for. I think that is where I made my mistake. This oldtimer was a bit rusty I think... :)

I can keep an 8x multi as my permanent setting right?

Thanks again ! Now to take things slowly and find the sweet spot according to Miahallen's steps. RAM seems fine.
 

Brutal-Force

Member
Joined
Feb 22, 2009
Yes but at that overclock, you could lower the Multi to 20X190 and get 800MHz DRAM freq.

You also can most likely turn your ram down to 7-7-7-20, if thats too low, then raise it to 8-8-8-21. But 7s should be possible.

Again, follow instructions. First Establish your Bclk. Second Establish Multi and Lowest Mem. timings. Third OC your CPU