[SOLVED] DDR2 GPU Work on DDR2 System, But not on DDR3 system

Based on what I know, any GPU will work in all PCIE slot. No matter if that is DDR2 or DDR3 system.
So I found this old GPU, https://www.gigabyte.com/Graphics-Card/GV-RX30HM256DP-RH#ov

The problem is, GPU will work and display in my DDR2 system, but when I try to install it on my DDR3 system, the GPU will not display.
My DDR3 system is work well with another GPU (AMD R7 250X), so that's not motherboard issue.

I know the GPU is old, I just want to use this GPU for display only. I just want to know why the GPU not work.
 
Solution
What motherboard is it and is it setup for uefi only boot? R7 supports uefi, obviously not for x300 requiring legacy. Most likely issue x300 is not compatible with the motherboard.
What motherboard is it and is it setup for uefi only boot? R7 supports uefi, obviously not for x300 requiring legacy. Most likely issue x300 is not compatible with the motherboard.

DDR2 system : Asus P5GC-MX/GBL , Pentium E2180
DDR3 system : Asus P5G41T-M LX3, C2Q 8200

Thanks for remind me about UEFI or Legacy, it should be legacy, but I'll check back soon as I come back home.
 
The X-series were the first generation on PCIe and UEFI wasn't a thing yet back then, so I agree you likely need to setup your motherboard for legacy boot if the option is available in BIOS.

I hope you got the X300 for free or at least much cheaper than a GT710.