cant overclock past 15%

Asus P5kpl-cm motherboard
June 8, 2010 at 15:50:02
Specs: Windows XP
Hi. i am having trouble overclocking my CPU. generally i started with a 2.5 ghz and my goal is around 3.2ghz.

got a q8300 @ 2.5ghz cpu and 2 2gb ddr2 800mhz kingston memory sticks

jsp-tech 400w led 12cmf real ezcool energy supplier (sorry bad english D:)

pro 775 arctic cooling (for cooling cpu)

so basically from what ive learned so far my mobo is really limited and bad for overclocking. my cpu multiplier is capped at 7.5. so i can only change my FSB speed. using AI overclocking ive been able to get a (for old games) stable 15% overclock. on newer games like crysis it crashes though, and the game kindof "stucks".

using manual instead of ai overcloking i get access to a few more options, but not many (limited bad mobo i hear).

anyway using manual i can still only raise the fsb (default was 333) to +15%, and not a bit more, or some old games starts to ger twitchy and crash.

ive tried many diffrent ram and voltage settings, but dont have much options to choose from.

any help from someone who is exeperienced in that area will be greatly appreciated!

edit: updated my bios yesterday, did not help a bit.

See More: cant overclock past 15%

June 9, 2010 at 01:21:42
u didn't list the v-card. Don't use AI overclocking. To hit 3.2ghz u have to overclock ram which i don't recommend so instead of 3.2ghz try 3ghz. Start to disable this settings.
-Disable spread spectrum
-disable eist aka speedstep
-disable cpu enhanced halt cie
-lock pcie to 100mhz
-disable cia2
underclock ram to ddr2 667 (333mhz) then pump cpu frequency to 400mhz cpu multi 7.5 save settings and see if the system boots. U can raise cpu frequency but if the system refuse to start increase ram/cpu voltage (0.1v).

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June 9, 2010 at 05:32:33
You *may* be able to hit 3.2GHz but 3.0GHz is a more realistic goal. As kuwese said, do NOT use AI overclocking. Configure all your BIOS settings manually. Shoot for 7.5 x 400MHz with the RAM running in sync at 400MHz frequency (800MHz DDR).

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June 9, 2010 at 09:06:35
ok, i should add some things.

first thing, i got a 9600gt nvidia geforce vcard.

second, i could boot XP with up to 417 FSB. trying anything higher wouldent boot, even with higher voltage.

3rd, my mobo is very lmited. i cant stress this enough. i got very little options to choose from. even for cpu, i cant really choose voltage, only got like 3 options (auto, 1.2v, 1.3v)

so with auto cpu voltage, 417 fsb xp boots, 418 fsb with w/e voltages on memory/cpu and xp wont boot.

now, for what you suggested:

i was able to disable (lol pun :D) enhanced halt state and speedstep. was able to set memory to 667hz and fsb to 400. im typing right now with those settings. i couldent find any other of the settings you mentioned anywhere in the bios.
no spread spectrum, saw something about pcie but nothing about locking it to 100hz, and nothing about cia2.

when im starting up the game, it starts stuttering and freezing right away.

any ideas what dto do this time?

also, why cant i OC past 3.0? i saw posts here of people with 2.4 basic clockspeed who got to 3.5 ghz after OC!

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June 9, 2010 at 11:16:10
when u pump cpu frequency memory frequency increase that the reason (u can still oc ram but u need to increase memory voltage). For eg. If u got ddr2 1066 u will reach very far.
I would like to download your mobo manual but my internet connection sucks plus i run out of credit.

Look careful for those settings.
U need to cpu stress software like prime 95

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June 9, 2010 at 11:30:45
"why cant i OC past 3.0?"

Because when you raise the CPU frequency higher than 400MHz, you begin overclocking the RAM. If you wanted to push the CPU up to 3.5GHz (which isn't likely with that board anyway), you'd need DDR2-1066 & it would have to be set to 800MHz.

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June 9, 2010 at 11:43:11
i have occt (some benchmarking software).

i did a cpu: linepack test with 400 fsb (my new goal) and it was successful. trying to play any 3d game however and the game will freeze...

so basically i got a bad mobo, bad cpu and a bad ram?

i was so noobish thinking "4 gb ram" was all good. next time i will know to look at the MHz :<

edit: i should say that with 800hz / 667hz i can still OC the exact same amount. maybe the crash ingame has something to do with the vcard? or maybe the board just hates high fsb?

also, i DLed the manual of the board myself. didnt get any help from it, its kinda useless imo.

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June 9, 2010 at 12:25:48
You should have payed attention to what you purchased!

The q8300 is a 1333FSB cpu,

The P5kpl-cm uses the G41 chipset and it's maximum FSB setting is 1333Mhz.

You can NOT OC this CPU any further without replacing the motherboard with a chipset that supports 1600Mhz FSB. While Asus allows the user to OC the chipset, it really never works as advertised(trust me, I have the P5K with the 945 chipset, familiar with Asus's bios). You will either need to purchase a new board, or new CPU. I would suggest a quad core in the q6XXX series as they use a 1067 FSB and OCing them is very easy and you won't be exceeding the chipset's spec FSB speed.

Secondly, with Asus boards, select the lowest RAM speed you can BEFORE you start to up the FSB speed. You'll notice for example after OC'ing the FSB from 800mhz to 1067mhz(example). The DDR2/3 speed will read one step higher than what you had set it at before OCing the FSB. Once you have the FSB set at the desired speed, then raise the RAM speed back to stock.

PowerMac 9600(1 ghz G4)
512mb RAM
50gb SCSI
ATi 9200 PCI

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June 9, 2010 at 18:31:21
"The P5kpl-cm uses the G41 chipset and it's maximum FSB setting is 1333Mhz"

Actually, the P5KPL-CM uses the even older G31 chipset but it is capable of 1600MHz FSB (by overclocking).

"i did a cpu: linepack test with 400 fsb (my new goal) and it was successful. trying to play any 3d game however and the game will freeze..."

Don't confuse frequency with FSB. Frequency is the actual speed, FSB is the QDR rating. Technically, when you say "400 fsb", the frequency is only 100MHz. You have your system set to 400MHz frequency, which is 1600MHz FSB.

I downloaded your manual too:

- AI overclocking MUST be set to manual
- CPU frequency should be set to 400MHz
- DRAM frequency should be set to 667MHz
- 1.8V Dual Over Voltage = RAM voltage - this should be set according to your RAM manufacturer's spec. *Most* DDR2 RAM is spec'd at 1.8v but much of the so-called "gaming RAM" runs at either 2.0v or 2.2v. Set it as close as you can get to the manufacturer's spec.
- 1.5V Over Voltage = PCIe voltage - there should be no reason to adjust this.
- VTT_CPU Over Voltage = CPU voltage - the Q8300, like most Intel CPUs, isn't given a set's given a voltage range of 0.85v to 1.3625v. Do you know what voltage it's defaulting to? Check the VCORE Voltage in the Hardware Monitor menu. If it's less than 1.3v, set the voltage to 1.3v. That's well within the safe range.
- 1.25V Over Voltage = northbridge chipset voltage - there should be no reason to adjust this.
- set the CPU ratio to manual, then the CPU ratio setting to 7.5x.
- disable both C1E & SpeedStep.
- you can also disable DRAM Timing by SPD then manually enter the timings. This isn't absolutely necessary though.

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June 10, 2010 at 06:43:06
ok so ive done everything you said with a few changes:

speedstep option dissapeared when i changed multiplier from auto to 7.5

didnt know what hardware monitor was, googling it shoes some bios screens, couldent find it there, but in cpu-z the cpu voltage never went below 1.2. so i changed it to 1.3 (max in the bios)

going through my memory manufactors website i couldent quite tell which one was mine. so i just tested it 4 times (with auto, 1.8,2.0,2.2). didnt work.

i am now posting with those settings.

the game however crashed.

maybe i should explain a bit more about the crash: the image freezes and the sounds from the last second are repeated for like 30 seconds, until its "freed" from the crash for 2 seconds and then crashes again.using fsb of 382 it almost never happens (once in 2 weeks maybe and then when its "freed" its ok) upping the fsb makes it more frequent, and around 398 its almost instant.

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June 10, 2010 at 09:24:23

That speed is OUT OF SPEC for that chipset! Just because Asus advertises it might be capable of 1600 mhz does NOT mean it is! That is why that speed has the "*" next to it on the website.

What will happen is you will get to a certain speed setting and then you will start running into data corruption issues, push it any further and it will not function!

You will need to acquire a motherboard that is capable of running a 1600mhz FSB WITHOUT overclocking the chipset! I can not spell it out clearer than that, you will reach maybe 10-15% with your current board, it's not the CPU's fault, it's the chipset!

PowerMac 9600(1 ghz G4)
512mb RAM
50gb SCSI
ATi 9200 PCI

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June 10, 2010 at 14:45:45
"ive done everything you said with a few changes"

All bets are off.

"didnt know what hardware monitor was"

It's a menu selection in the BIOS & is shown in the BIOS chapter of the manual.

"going through my memory manufactors website i couldent quite tell which one was mine"

That's why they print labels & attach them to the memory stick.

"using fsb of 382"

382 is NOT the FSB, it's the frequency!

"upping the fsb makes it more frequent, and around 398"

398 is NOT the FSB, it's the frequency!

Try increasing the northbridge chipset voltage.

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