Upgrade your Optiplex 755 CPU!
Upgrade your Optiplex 755 CPU!
I'm planning to replace an old Otiplex 755 DT. Its processor is really slow, so I need a better choice. The motherboard is DR845 with chipset Q35 and LGA 775 socket.
Don't invest in unnecessary expenses. Even the top-tier processor is nothing compared to a used Dell for that price. It's likely to have an outdated i5 2400 and won't fit any modern CPU in its socket. That i5 isn't worth keeping, and the machine is essentially useless now.
You could include some Core2Quad, but honestly... for the cost of getting those CPUs shipped out, a newer OptiPlex with something solid is worth it.
You've selected the Core 2 series quite well. You may need to refresh the BIOS, but they're accessible through Dell's support portal once you enter the service code. https://www.cpu-upgrade.com/mb-Intel_(ch...press.html Unless you're assembling an XP system, skip it.
And this doesn't include the resale worth of that 755 model, because even with a low-end CPU, it should still fetch at least $10. A big jump from upgrading would be to the Q6600. You just need to tweak the BIOS to 333 bsel for 3GHz, but that 65nm version isn't great at speed and requires a lot of voltage—so don't push it higher just for board specs. The heat output would be an issue too, especially with max safe voltage around 1.65V at 45nm. For better performance, consider Q6600 or X3430/X3440 with a decent 45nm quad. You don’t need top RAM, just a solid board that hits 220+ MHz. The Gigabyte H55M UD2H is a solid choice, some builders even hit 320 MHz. X34X or similar with a good H55/P55 combo works too, and you won’t need expensive RAM. But if you want DDR3, it’s not worth it—most boards still support 2000MHz anyway. High-speed 2GB DDR2 sticks are rare, and most DDR2 info is outdated or hard to find.