First post, by Masterchief79
Hey guys,
after successfully transplanting the GPU of my first FX1300 onto a FX5950 Ultra, I wanna do more with these cards.
I want to turn another FX1300 into a PCX5950 (128MB@350/275 -> 256MB@475/425MHz).
This is mainly because I can and I want to. A NV38 based PCI-E card doesn't really have any real benefits to me, I have plenty of AGP systems around. But I'm a collector and semi-professional technician of retro-hardware and today I decided I would like to have a PCX5950. 😁
Here are the challenges I'm looking at:
- The 2.8ns memory chips will need to be swapped. I have two defective FX5950 Ultras here with 2.0ns Hynix mem so I could just swap those chips over. Problem: I would end up with a 128MB card since the Quadro only has 8 memory chips opposed to the 16 on a 5950U (front and back). I want to double the memory if possible.
- Afaik there are no fitting hynix memory chips with deliver 8x32 = 256MB. There are AFM-25 on a 9800XT but they are specified to 2.5ns (400MHz) and would probably not do 425MHz reliably. Might be worth a shot though. I could do the rest with timings.
- not currently sure if other manufacturers like Samsung or Infineon did GDDR ramchips in this configuration - let me know
- Samsung GC20 or GC16 is 144FBGA but is probably not pin compatible, since it's GDDR3 memory
- Voltmod for the GPU (1.35 -> 1,55V) - should be no big issue.
- possibly Voltmod for the memory - should be no big issue.
- better cooling for the GPU and mem Chips (VF700 is available).
Swapping memory modules from a different brand onto the card usually requires you to modify the memory straps. I've never done that before but I'm told usually they show the configuration in the schematics.
Questions at this stage:
- Which card had 256MB GDDR memory in a 8 chip configuration, ideally with clockspeeds higher than 400MHz (<2.5ns)?
- schematics for some 5900 series graphics card, no matter if AGP or PCI-E, or some old Nvidia schematics in general (anything between NV25 and G71) - found some
- information about memory straps and changing them between memory brands
- general input or questions welcome
This thread already helped: PCIE Graphics Card and it had a schematic inside which I attached below.
New question: Since the PCX5900 is GDDR-based, and the PCX5950 allegedly GDDR3-based:
- is the pinout compatible? There seems to be some differences but there's also a lot of similar stuff
- is the NV38 GPUs memory controller able to handle GDDR3 memory? Wasn't there a FX5700 Ultra GDDR3 at one point? Is the PCB identical? That's comparing to GDDR2 though
Information on that: https://hothardware.com/reviews/nvidia-geforc … -with-gddr3-ram
Currently looks like GDDR2 and GDDR3 are pin-compatible but GDDR is not to either of those two.
So it looks like the only feasible option is to get some Hynix AFM-25 memory and hope it clocks to 425MHz. I have a buddy who has some defective 9800XTs. I don't know where else I could steal it from - input welcome.
Next question: What am I going to do BIOS-wise? I'm not too familiar to modifying BIOS files outside of Nibitor and the like. Techpowerup doesn't host files that old and even if they did, I'm not sure there are original PCX5950 files anywhere (if they even existed). The problem is memory size of course, everything else should be easily modified. I think I'm gonna need help on that too.
