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AMD® Phenom™ II Overclocking Thread

Surely the clock speed makes far more difference to performance than anything else... ?

This shows tests on various different memory timings / speeds. TBH it looks like these settings do make a measurable difference in benchmark tests but are they really enough to notice while using the pc?

I am not so sure.
 
that's just memory timings and already on some you can see 5-15% diff.
Add HT/NB to that and you get quite a lot.

I'd do some tests later this evenining with max ht/nb/ram and basic settings.
Tho aint got gpu now so bit limited with benchs.

Ninja edit:

Also, as it might not quite show in the cpu benchs so much, it will give a lot more boost in gaming with high end GPU where it starts getting limited by CPU/mem bandwith.
And latency helps a lot as well.
 
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I would be really interested to see that.

When you say HT I am assuming you are referring to the hypertransport link rather than the hypertransport reference clock?

I got my nb to 2600 and my ht to something similar but I never noticed much difference. Although at that stage I was changing so many settings all the time that I probably never had much time to notice and of the practical effects!:D
 
Uriel said:
More on the HT link balance in 3DMark06

With CPU @ 3.3 GHz, NB @ 2.4 GHz, HT @ 1.8GHz, RAM @ DDR2 800 CL6, Stock HD4850, I got 14024.

With CPU @ 3.3 GHz, NB @ 2.1 GHz, HT @ 2.1GHz, RAM @ DDR2 600 CL6, Stock HD4850, I got 14036. New best time on this rig and I was able to drop both NB and RAM speed, while bumping up HT for a better score.

Don't know if it's anything in particular but you'l notice a lot of stuff fits nicely into the 300 times table :p
Click to expand...

Your ram is too slow to use the NB clock and your graphics card is too slow to pick up the CPU difference in 3dmark (using the CPU score might be more useful).
 
Meaker said:
Your ram is too slow to use the NB clock and your graphics card is too slow to pick up the CPU difference in 3dmark (using the CPU score might be more useful).
Click to expand...

Wrong (to an extent). It scales with NB, it scales with HT. Surprisingly changing RAM from 600 to 800 has little effect. See previous my posts on scaling.

CPU unlocking and clocking got me from around 10k to 14k with the same graphics card.

Edit: 3dMark06 score isn't a straight bottleneck situation. For framerates in games your comments might be valid. However I seem to consistenly get better results running RAM in 1:1 sync with my HT Ref frequcency, rather than at its rated speed at 4:3. May do a 2400 NB/HT run at some point to see how it looks.

Not going to be buying better RAM to go with this CPU as my board supports DDR3 as well as DDR2. The CPU is AM2+ so is restricted to DDR2. I did plan this as a stop-gap / experimental CPU (why not for £36?) but given the unlock and decent overclock I'm more tempted to keep it until the RAM is really restrictive. Graphics card will be on the 'to do' list whenever it actually restricts me in games but everything aside from crysis and PhysX titles runs fine. Crossfire could also be an option, I suppose but 512MB vRAM combined with relatively slow DDR2 would be a limiting factor.

Article on scaling with various parameters (RAM, HT, NB etc) on an AM2+ Phenom II here: http://www.madshrimps.be/?action=getarticle&number=4&artpage=3965&articID=909.
 
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Hey all,

Just installed my new Phenom II X4 945
untitled.jpg


I've never over clocked anything in my life so I reckon now's a good time to have a go. What safe clocks would I be able to get out of this?

Thanks.
 
have you got a decent cooler or stock one first.

most will do 3.8 no problem but like said need a reasonable cooler if its the same stock cooler as the 955 or 965 its good for 3.5 or 3.6 after that get something decent like a titan fenrir , true , baram, some say h50 but ive noticed quite a few with higher temps than the above coolers mentioned. also remeber the size of these coolers as most are big !

good luck with te overclock and dont be scared its pretty easy with these babys up until 3.8 then it gets tricky :D
 
~>Dg<~ said:
have you got a decent cooler or stock one first.

most will do 3.8 no problem but like said need a reasonable cooler if its the same stock cooler as the 955 or 965 its good for 3.5 or 3.6 after that get something decent like a titan fenrir , true , baram, some say h50 but ive noticed quite a few with higher temps than the above coolers mentioned. also remeber the size of these coolers as most are big !

good luck with te overclock and dont be scared its pretty easy with these babys up until 3.8 then it gets tricky :D
Click to expand...

Looks half decent, it's a chunky one with all copper pipes going through the middle of it to expel the heat. I don't want to go overboard with this over clock thing, as long as it's stable then i'm satisfied.

Do I do it through the BIOS screen thing, pressing delete when my PC starts up?
 
buchtis said:
Do I do it through the BIOS screen thing, pressing delete when my PC starts up?
Click to expand...

I think so. People with newer motherboards can use AMD overdrive software in Windows but I don't think it works on your board.

Just a bit of advice. Your CPU will use more electricity once you start upping the voltages. What's the maximum CPU wattage recommended for your board? You can probably extimate wattage based on what each stock AMD CPU uses at stock voltage for each given speed. If you clock yours to 965 (3.4GHz) levels at the same voltage as a 965 @ stock it will be pulling around 125w or 140w depending ons stepping. You don't want to exceed it by much or you could kiss goodby to your motherboard (or possibly experience a slow and painful deterioration where everything's fine with the clock at first but it will get gradually more unstable as time goes on). If your CPU is kind to you, you might be able to overclock while undervolting but that would need some luck.

As you're on an AM2 board, you might not be able to set the CPU-NB frequency or voltage. That may scupper your chances of gettinga higher overclock.
 
ok the setting below were ok until i ran prime95, can someone give me more settings to try ?

CPU RATIO + VOLTAGE
under that heading is
CPU/RATIO------17
CPU/NB FREQ-----auto
CPU OVER VOTAGE------1.45
VDDNB OVER VOTAGE------AUTO
LOADLINE CALIBRATION----0%

it doubt it will take any higher settings but ic ant be sure
 
PhoenixUK said:
No point going 4ghz if your HT/NB and ram have crappy low settings..
Click to expand...

NB & HT are currently 2400 MHz, 2600 MHz on either works but isn't 100% stable. In the end I'm not really interested in shoving 1.55 vcore thru my shiny new CPU along with similar voltages on the CPU-NB & HT bus (24x7) just to get another 5-10% performance (under limited circumstances) & a bigger e-peen :D
 
Its good practice to use more than 1 stress testing tool to test for ultimate stability. Prime95 is popular, also how many passes of IBT have you done? Everyone has their own opinion but I'd reckon you'd want it to run for at least 4 hours to give it a chance to REALLY test out your CPU.
 
Ooops

Martini1991 said:
I messed up setting up my loop rofl.
So, new liquidant ordered for Tuesday delivery, possible wednesday due to college.
Click to expand...

At least your loop didn't leak all over a 4870 & a brand new Gigabyte GA-790XTA-UD4 :eek:

Luckily I use MCT-5 so after a good mopping up & an hour with a hair dryer I got away with a burnt out PCI slot & a knackered X-Fi Xtreme Gamer Fatal1ty Professional :mad:

Lesson learn't...if U take a waterblock apart make sure U line the bloody o-ring up properly otherwise no matter how tightly U tighten up the screws its still gonna leak.
 
Hey guys, i have just revisited clocking my 940 and have had much better results after a HSF reseat and better thermal paste. I have it 3.6 stable and have now moved up to 3.75 however i have encountered a couple of issues:
In the bios i set the vcore voltage and the cpu-nb voltage to 1.55 and 1.3 respecively, but in cpu-z and amd overdrive it reports it 0.1v lower than this for each value

it doesnt seem like much of a problem, but, it means that when in the bios i set cpu vcoe to 1.6 (to get 1.5 in cpu-z) it wont start becuase of an "overvolatge error"

which of the readings is correct? as in the bios it reports 1.587 actual, buti get 1.4875 in software programs. Would a bios update sort this problem?

Cheers
 
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I fancy boys said:
which of the readings is correct? as in the bios it reports 1.587 actual, buti get 1.4875 in software programs. Would a bios update sort this problem?

Cheers
Click to expand...

Hi,

AMD overdrive is not supposed to work with BIOS OCed CPUs so most of the overdrive settings show stock settings and these are inaccurate.

CPU-Z should show real info.
You might also try to disable (or set to 0) the Loadline Calibration.
 
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