First attempt to overclock - help required

MT01XP

MT01XP

MT01XP

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CPU: A64 3000+ (754) Venice
Mobo: Gigabyte GA-K8NS
Memory: 1Gb DDR-SDRAM PC3200 (2.5,3,3,7)


I've read the 'Overclocking guide for newbies' Sticky/FAQ and have been trying to take the first few steps to overclock the rig above.

Firstly, from what I've read on the net, the nForce3 250 chipset on the mobo is supposed to lock PCI/AGP as standard. Is this correct?

Secondly, it's not clear to me how I can increment the FSB in the BIOS, as I'm given the following options in the Frequency/Voltage Control menu:

  • CPU OverClock in MHz
    200MHz ~ 455MHz Increase CPU frequency as user selected.

  • AGP OverClock in MHz
    66MHz ~ 100MHz Increase AGP frequency as user selected.

  • K8 CPU Clock Ratio
    Default Set K8 CPU Clock Ratio to CPU factory default. (Default value)
    x4 800Mhz ~ x10 2000Mhz.Set K8 CPU Clock Ratio from x4 800Mhz to x10 2000Mhz.

  • CPU Voltage Control
    Normal Set VDDQ(AGP) voltage as AGP required. (Default value)
    +5% Increase CPU voltage +5%.
    +7.5% Increase CPU voltage +7.5%.
    +10% Increase CPU voltage +10%.

  • VDDQ (AGP) Voltage Control
    Normal Set VDDQ(AGP) voltage as AGP required. (Default value)
    +0.1v Increase VDDQ(AGP) voltage +0.1V.
    +0.2v Increase VDDQ(AGP) voltage +0.2V.
    +0.3v Increase VDDQ(AGP) voltage +0.3V.

  • DDR voltage control
    Normal Supply DDR voltage as DDR required. (Default value)
    +0.1v Increase DDR voltage +0.1V.
    +0.2v Increase DDR voltage +0.2V.

Can anyone advise please?
 
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Here are the main BIOS menus:

  • Standard CMOS Features
    This setup page includes all the items in standard compatible BIOS.

  • Advanced BIOS Features
    This setup page includes all the items of Award special enhanced features.

  • Integrated Peripherals
    This setup page includes all onboard peripherals.

  • Power Management Setup
    This setup page includes all the items of Green function features.

  • PnP/PCI Configuration
    This setup page includes all the configurations of PCI & PnP ISA resources.

  • PC Health Status
    This setup page is the System auto detect Temperature, voltage, fan, speed.

  • Frequency/Voltage Control
    This setup page is control CPU clock and frequency ratio.

  • Top Performance
    If you wish to maximize the performance of your system, set "Top Performance" as "Enabled".
 
if you want to oc the nf3 250, you need to do a few things..
up the pci freq by 1 mhz.. iirc, it isn't locked. cpu thermal throttling is bad, switch it off. Also the LDT (or HTT) won't run @ x4 with an fsb overclock.. i'm guessing it's 800 normally, so if you want the fsb to be 250, then x3 is the max you can have the htt at.. the htt on my old nf3250 wouldnt oc for anything!
lastly, the fsb increments will be in
*CPU OverClock in MHz*
to change it, it'll either be numerical (type it in on your numpad, makesure numlock is on), +/- keys, or pgUP/pgDOWN keys.
hope that get's you started.. there's a million other things to learn about getting a high/stable overclock, so good luck!
 
uvmain said:
if you want to oc the nf3 250, you need to do a few things..
up the pci freq by 1 mhz.. iirc, it isn't locked. cpu thermal throttling is bad, switch it off. Also the LDT (or HTT) won't run @ x4 with an fsb overclock.. i'm guessing it's 800 normally, so if you want the fsb to be 250, then x3 is the max you can have the htt at.. the htt on my old nf3250 wouldnt oc for anything!
lastly, the fsb increments will be in
*CPU OverClock in MHz*
to change it, it'll either be numerical (type it in on your numpad, makesure numlock is on), +/- keys, or pgUP/pgDOWN keys.
hope that get's you started.. there's a million other things to learn about getting a high/stable overclock, so good luck!
Click to expand...

Thanks for the feedback uvmain. :)

Am I correct in assuming that *HT Frequency [4x]* is the LDT / HTT Multiplier?

In order to find the max of my CPU am I right in thinking I need to set the *HT Frequency* to 3x, set my *Max Memclock (Mhz)* to say 133 (Mhz) and increase *CPU OverClock in MHz* in 50Mhz increments?
 
yeah, that is the HT multiplier.

I always do a bit of maths and take my CPU up in incriments of 0.05Ghz.

as has already been mentioned, there's a million and one things to think about when overclocking, but to keep is simple do the following:

Drop HT to 3x
Drop RAM speeds to DDR300 or DDR266 (may show up as 1/2 those values)
Raise the FSB in incriments of your choosing until the system won't boot, then back it off until it will.

Then you're into testing for a stable overclock, using a program like Prime95 to make sure the system is stable at those speeds.

A perfect overclock (for me :p) is

high (like running my 3000+ at 2.6-3Ghz)
Tight (all RAM timings as tight as they'll go, HTT as high as it'll go etc.)
Cool (below 50'C and with as few extra volts on Vcore as possible)
Stable (prime95 stable for more than 5 hours)


As you can guess there's a tonne of things to watch out for, from RAM timings to cooling to HTT speeds.

hope this was informative and good luck! :D

Mike
 
Thanks for the input Mikebert4

I've set the HT to 3x, Memory Speed to 133Mhz and have so far incremented the FSB to 245Mhz.



According to EasyTune:

CPU Idle = 32'C
CPU after 8M Super Pi = 40'C

Super Pi completes an 8M test without any problems, however I'm curious as to what it will display if there is a problem?

Since I'm on stock cooling I'm a little cautious about ramping up the FSB further.

How do the above stats sound to you?

Thanks in advance! :)
 
Just keep going with the HTT increments mate it's doing very well so far without have to increase the Vcore. Once you hit above DDR400 again just drop the memory divider down to 100 and keep going with the HTT.

The NF3 250Gb is a very good chipset IMO and I'm especially impressed with my DFI board. I'm guessing but I suspect you'll be able to hit around 2.8 GHz without much of a Vcore increase and possibly a lot further when you eventually have to increase Vcore.

With stock cooling I'd probably go for a max of 1.5v for now which should still give you good temps of around 50c or less.

Also I recommend downloading Next Sensor (I've a thread on here about it if you need help finding/configuring it) and configure it so it shows the CPU's on-die thermal diode temperature so you have a more accurate reading of the CPU temperature. The on-die thermal diode temperature will typically be around 7c to 15c higher than the motherboard reported CPU temperature and I suggest you make sure it stays below 60c or so on stock cooling.
 
OK, I replaced the stock cooler with a Freezer 64 Pro and subsequently gone up to HTT @ 255Mhz (see below) at which point 8M Super Pi crashes




CPU Idle = 33'C
CPU after 8M Super Pi: 38'C

I understand that I should start to increment the CPU voltage by 0.05V, up to a maximum CPU voltage of 1.5V-1.6V (to try and regain some stability), however I'm not sure which option in the BIOS I need to change as the CPU Voltage Control only offers a percentage change. :confused:

  • CPU Voltage Control
    Normal Set VDDQ(AGP) voltage as AGP required. (Default value)
    +5% Increase CPU voltage +5%.
    +7.5% Increase CPU voltage +7.5%.
    +10% Increase CPU voltage +10%.
 
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Some motherboards allow the default Vcore to be changed up to 1.55v but I guess yours must not have that option so all you can do is up it via one of those percentages.
 
str said:
Some motherboards allow the default Vcore to be changed up to 1.55v but I guess yours must not have that option so all you can do is up it via one of those percentages.
Click to expand...

I set the CPU Voltage to +10% which yeilded 1.55V.

8M Super Pi crashed @ 2750Mhz (CPU Idle = 34'C CPU load = 40'C) but passed at 2700Mhz (CPU Idle = 34'C CPU load = 40'C), so I'll leave prime95 running overnight to check stability.

Any ideas as to why the system crashes, even though the load temp is only 40'C?

If all goes well, then I'll start trying to get my head around finding the maximum of my memory. :)
 
There's no easy way to tell until you have tested using all three Prime95 torture tests. The Small FFTs generally tests the CPU the most especially heat wise. The In-place FFTs is the CPU and the memory and the Blend test will mostly show up memory/memory controller problems.

Also S&M is also useful to find out if your overclock is too much as it'll freeze the system requiring a reset if you've pushed it too far. Be sure to monitor S&M when it's running though as it's quite a stress on your system and you wouldn't want it breaking anything.

I recommend you get Next Sensor to monitor the on-die thermal diode temp rather than relying on your motherboard's CPU temp reporting as the on-die will give you a clearer indication of the heat being generated.

Also 40c is good at that Vcore so you probably have a good amount of air intake via a front case fan as well as good removal of the heat via your PSU fan and any rear case fans.

Last thing, the Freezer 64 Pro is great at dissipating the heat from the CPU so definately a good choice but you shouldn't allow anything to change the speed of the fan (motherboard/fan controller) as at slower speeds it leaks oil or some such liquid from the fan onto the motherboard but at full speed it appears to be fine.
 
str said:
Last thing, the Freezer 64 Pro is great at dissipating the heat from the CPU so definately a good choice but you shouldn't allow anything to change the speed of the fan (motherboard/fan controller) as at slower speeds it leaks oil or some such liquid from the fan onto the motherboard but at full speed it appears to be fine.
Click to expand...


This is true. The Freezer 64 Pro doesn't like the way most Motherboards manage speeds (using Pulse-width modulation = PWM) and it'll spew out all it's gooey innards (used for lubricating the bearings) Luckily this stuff is non-conductive... but it's not nice and the Fan could jam after a while.

When i switched to Watercooling, I tested my old Freezer 64 Pro (fantastic HFS IMO) with PWM, and sure enough it spewed after around an hour at 1/2 speed.

With that HSF and decent case airflow (120mm high CFM's in front &rear of Akasa Eclipse-62) I weas getting load temps of 40-45'C as well, rising to 50'C when I was using 1.6v Vcore



moving onto the overclocking...

I struggled to break 2.7Ghz as well, I found that my RAM wasn't too happy running as DDR 100, and the HTT wouldn't budge.

I found the best performance/stability balance with the following setup:

Ram at DDR333
FSB at 289Mhz
Vcore at 1.5v (though 1.6v is safe for 24/7 with that HSF)
VRAM at 2.8
HTx at 3x
Ram timings 3,4,3,8 1T*


*dropping from 2T command rate to 1T = mega performance boost. do it! :p


This setup runs the ram at ~240Mhz (DDR 480 to put it in perspective)
the CPU at 2.6Ghz

and keeps the HTT bus relatively happy.

overclocking the RAM in this way ment that I had a very nice, balanced system and I wasn't strangling any component (even though the HTT was down round the 850Mhz mark... it didn't really affect preformance too much)

well... thats my story, I went for a more rounded Overclock and I run it 24/7.

just somthing for you to consider, no point having a silly-clocked CPU if your RAM is chugging along at 150Mhz now issit? :p
 
str said:
There's no easy way to tell until you have tested using all three Prime95 torture tests. The Small FFTs generally tests the CPU the most especially heat wise. The In-place FFTs is the CPU and the memory and the Blend test will mostly show up memory/memory controller problems.

Also S&M is also useful to find out if your overclock is too much as it'll freeze the system requiring a reset if you've pushed it too far. Be sure to monitor S&M when it's running though as it's quite a stress on your system and you wouldn't want it breaking anything.
Click to expand...

I'll bear that in mind. Thanks.


str said:
I recommend you get Next Sensor to monitor the on-die thermal diode temp rather than relying on your motherboard's CPU temp reporting as the on-die will give you a clearer indication of the heat being generated.
Click to expand...

Next Sensor doesn't seem to work properly for me (although the K8ThrmDiode looks about right).

Under load it reads:

Processor: 6.00'C
K8ThrmDiode: 49.00'C
NorthBridge: 40.00'C

Idle it reads:

Processor: 253.00'C
K8ThrmDiode: 38.00'C
NorthBridge: 33.00'C

Go figure!

(FYI: The Automatic Settings on the Control Tab have been set for the appropriate sensor, ITE IT87xxF)


str said:
Also 40c is good at that Vcore so you probably have a good amount of air intake via a front case fan as well as good removal of the heat via your PSU fan and any rear case fans.
Click to expand...

God bless the Lian Li PC7+ :cool:


str said:
Last thing, the Freezer 64 Pro is great at dissipating the heat from the CPU so definately a good choice but you shouldn't allow anything to change the speed of the fan (motherboard/fan controller) as at slower speeds it leaks oil or some such liquid from the fan onto the motherboard but at full speed it appears to be fine.
Click to expand...

I don't have a fan controller fitted. Is the motherbord/BIOS likely to have some kind of feature that would change the speed of the Freezer 64?
 
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