Ancient GPU For Cheap Overclocking

jplum1556 · October 4, 2020

I want to dabble in overclocking this winter as something to do while I'm hibernating indoors and already have an old QX9650 CPU, Gigabyte EP45 mobo, and some cheap ram. I'm trying to find an older high end gpu, likely from a similar era that has lots of overclocking headroom and some info on hard modding the card. Anyone have suggestions or what GPU shall be my victim?

Warm regards,

-Plum

SkilledRebuilds · October 4, 2020

HD7950 (more power)

HD7850 (more budget)
Grab any DUALBIOS card with Dualfans or more,.. head on over to Techpowerup GPU Bios database, learn how to flash, increase power, aim for over 20% core gains, experiment with Undervolting, or Declocking Ram to allow Higher Core Power budget.

Applefreak · October 4, 2020

11 minutes ago, jplum1556 said:

I want to dabble in overclocking this winter as something to do while I'm hibernating indoors and already have an old QX9650 CPU, Gigabyte EP45 mobo, and some cheap ram. I'm trying to find an older high end gpu, likely from a similar era that has lots of overclocking headroom and some info on hard modding the card. Anyone have suggestions or what GPU shall be my victim?

Warm regards,

-Plum

Before you try and crank things up a word of caution. The Core 2 Quad CPUs have an external FSB or Front Side Bus that ties the CPU to the Northbridge, which connects then to PCI-e and RAM and the Southbridge (USB, normal PCI etc.).

Unless you know how to split the FSB clock and the CPU clock (I am not sure if the P45 can do that, the X series was for OC back then), you will overlclock the PCI-e bus and RAM at the same time. That can be really dangerous if you are just tinkering around. Make sure to read into OC on old boards (unless you are ancient like me and already know that, in which case, let's fry some eggs if you know what I mean).

If your CPU is a C stepping, you will not be able to push it far, you would want a E stepping part to really max that frequency. Watercooling will be your friend here, some modern AIOs do support Socket 775 if you are to lazy for a custom loop. BTW. aftermarket cooling is a must if you plan OC on older graphics cards. Keep in mind that none of the older components had any sort of boost mode and rarely any kind of throttling to protect themselves. Emergency shutdowns due to overheating were not working so if you went to far, that's ist, game over.

Maybe start with something reasonably new like AMD HD series or GTX 700, those can be found working below 50.- at the moment (should be less if you ask me). Some GTX 200 cards did overclock really well.

jplum1556 · October 4, 2020

32 minutes ago, Applefreak said:

Before you try and crank things up a word of caution. The Core 2 Quad CPUs have an external FSB or Front Side Bus that ties the CPU to the Northbridge, which connects then to PCI-e and RAM and the Southbridge (USB, normal PCI etc.).

Unless you know how to split the FSB clock and the CPU clock (I am not sure if the P45 can do that, the X series was for OC back then), you will overlclock the PCI-e bus and RAM at the same time. That can be really dangerous if you are just tinkering around. Make sure to read into OC on old boards (unless you are ancient like me and already know that, in which case, let's fry some eggs if you know what I mean).

If your CPU is a C stepping, you will not be able to push it far, you would want a E stepping part to really max that frequency. Watercooling will be your friend here, some modern AIOs do support Socket 775 if you are to lazy for a custom loop. BTW. aftermarket cooling is a must if you plan OC on older graphics cards. Keep in mind that none of the older components had any sort of boost mode and rarely any kind of throttling to protect themselves. Emergency shutdowns due to overheating were not working so if you went to far, that's ist, game over.

Maybe start with something reasonably new like AMD HD series or GTX 700, those can be found working below 50.- at the moment (should be less if you ask me). Some GTX 200 cards did overclock really well.

Yea, I vaguely remember the FSB and PCIE frequency being tied to an increase in CPU speed back when I was a wee lad building my first computer. From what I understand so far is the QX9650 has an unlocked multiplier so I should not have to worry much about the FSB frequency. Still reading up on how to overclock hardware in that era so I may be wrong. This is not going to be a pc used daily so not looking at liquid cooling, it's just going to be used for messing around with overclocking on free weekends and cooling with dry ice.

52 minutes ago, SkilledRebuilds said:

HD7950 (more power)

HD7850 (more budget)
Grab any DUALBIOS card with Dualfans or more,.. head on over to Techpowerup GPU Bios database, learn how to flash, increase power, aim for over 20% core gains, experiment with Undervolting, or Declocking Ram to allow Higher Core Power budget.

Good call on finding a dual bios card. It looks like the ATI 7850s and 7950s have quite a bit of info online on overclocking them and prices seem reasonable for picking up used cards.