Overclocking the Athlon II 250

[Lovansoft]

A few months ago I sprang for a few new parts to replace my aging P4 and went with:

Gigabyte GA-MA790GP-DS4H
AMD Athlon II 250
GSkill F2-8500CL5D-4GBPK (DDR2-1066)

Just for reference, here's the stock settings so noone needs to look them up:
Athlon II 250:
HT Transport Link - 2000
HT Multi - 15
Base Freq - 200
Northbridge Ref - 2000

GSkill RAM:
CAS# Latency - 5T
RAS to CAS R/W Delay - 5T
Row Precharge Time - 5T
Minimum RAS Active Time - 15T
1T/2T Command Timing - 2T
TwTr Command Delay - 3T
Trfc0 for Dimm(x) 127.5ns
Write Recovery Time - 6T
Precharge Time - 3T
Row Cycle Time - 25T
RAS to RAS Delay - 3T

OK, so the best way I've found to OC without upping the voltage on the CPU is to change the Base Freq from 200 to 240. This puts the CPU from 3Ghz to 3.6Ghz and the HT Link and NB Freq at 2.4Ghz. Dropping the Multi's to lower the HT and NB didn't give me any more room so I'm leaving it up. It's Stable, so I'm happy.

My question comes to the RAM. I had to drop the multi from 5.33x to 4x which runs it at 960Mhz. I'd like to bump that multi back up to 5.33x which would OC my RAM to 1280Mhz. That' seems a bit much but I've seen a few results such as this one that make it seem possible as they were able to get theirs to up 1380 (though it's a 2x1GB back, not the 2x2GB pack like mine). I don't mind relaxing the timings, but my MB keeps dropping the Multi back down. I think that's a safety measure.

Any ideas on what settings to use? I've tried relaxing the timins from 5T to 7T to no avail, but cant say I really know what the other settings are. I'm OK with the OC, but would like to get the RAM up if I could.

Thanks in advance....

 

[formulav8]

The possible better way would probably be to focus on getting half-way decent timings and then find the max clockspeed. Theres isn't a whole lot to be gained from higher memory bandwidth. Tighter timings at a 'decent' clockspeed might be the better way.

Either way, you may need to up your rams voltage to get it to the speeds you want. Also every memory controller will behave alittle differently. So just because someones cpu was able to push the ram to 1333mhz doesn't mean another cpu of the same model would be able to.

Anyways, IMO I would rather run my ram at decent timings like 5ns and 1066mhz than running at 7ns timings and 1333mhz.

Every person has their own opinion on this. So just take my opinion as a grain of salt.

PS: Crank that northbridge as high as it will go as well. Depite not having Level3 cache there ARE gains to be had by overclocking the memory controller itself. My own personal testing has seen a 600mhz-800mhz clockspeed increase in the cacheless northbridge bring gains up to 4%-11% in various area's (Gaming saw the biggest). So if your looking to sqeeze out all you can give that a try as well.


Jason

 

[Lovansoft]

How high can the NB go? I thought 20% was good. How much more do you think I'll get? And how would I do it without upping voltage?

 

[hdfxst]

I have an x2 240 with the same ram and at 2.0 volts 1100 was as far as i could go without backing off the timing.Here's what i've been running at for about 10 months now http://img51.imageshack.us/i/biose.jpg/ you can see that the ram is running at 1068 and ram settings http://img37.imageshack.us/i/bios2b.jpg/

 

[heyheybooboo]

I don't mind relaxing the timings, but my MB keeps dropping the Multi back down. I think that's a safety measure.

That is most likely 'Cool & Quiet' - the AMD power saving feature which will drop the CPU voltage and multi to 4x when loads are minimal (no worries, but some folks feel they can OC higher when C&Q is disabled).

How high can the NB go? I thought 20% was good. How much more do you think I'll get? And how would I do it without upping voltage?

The 'uber-enthusiasts' at XS are passing 3000MHz. Without a volt bump 2400MHz is a slam-dunk. With a slight bump you should reach 2700-2800MHz.

General rule of thumb for PhII/AthII: For each 10% you increase the NB/IMC, memory bandwidth is increased 3-4% and latency is reduced 3-4% (maybe a touch more with the AthIIs).


If you wish to bring your RAMs up to spec speed you can up the clock to 250MHz. If that affects stability, you can try 14.5x250MHz (or do a bit of volt tinkering - AMD spec is 0.85-1.425V with a max temp of 74c).

Your GA-MA790GP-DS4H was a great pick. Should be fun in bringing out the best in that 2-fiddy Regor




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[formulav8]

How high can the NB go? I thought 20% was good. How much more do you think I'll get? And how would I do it without upping voltage?

The post above has accurate info.

In my own testing I have a Single Core Sempron 140 that I unlocked to a 4400e Athlon II Dual Core (Not a real AMD released SKU btw).

I ran the cpu clockspeed to 3807mhz @ 1.52v with pretty good stability. I then was able to get 2820mhz on the northbridge. I never tried to run the NB at stock voltage and instead I just went ahead and raised the voltage on the NB anyways so I didn't have to deal with stability testing.

I saw almost a 6% decrease in memory latency and some increase in total bandwidth.

SuperPI only gained about 2.5% but games like TMNations got a solid 10%-11% increase and Cinebench R10 opengl saw a very nice 10%-11% gain as well. This was with the ram running at only 282mhz @ 5-5-5-15-20-1T Timings. (I had such a low ram clock for testing specifically the effects of lower memory controller latecy). The improvements should be better with higher memory clockspeed. Definitely worth going the extra mile to tinker with the Northbridge even without the Level 3 cache...


Jason