BUG Multipar greys out GPU with Nvidia 5060Ti

[betagitman]

Windows 10 Pro 64 bit, 32GB RAM, core i9-9900k, 931GB SSD
ASUS Dual GeForce RTX™ 5060 Ti White Edition

I have noticed that the in the OPTIONS control panel
"Enable GPU acceleration is unchecked and grayed out (disabled?).
but "SSSE3 CLMUL JIT AVX2" they're all enabled and checked.
The Nvidia driver is recent, 581.57 released 14 Oct 2025
Multipar 1.3.3.5

Thank you, I think the error is reproducible easily
John

[Yutaka-Sawada]

Thanks John for bug report. NVIDIA seems to end OpenCL support for 32-bit application at recent RTX 50.

Nvidia's poor RTX 50 compute test results due to missing 32-bit OpenCL support, says PassMark

NVIDIA's 32-Bit PhysX Waves Goodbye with GeForce RTX 50 Series Ending 32-Bit CUDA Software Support

Because MultiPar GUI is 32-bit, it cannot detect OpenCL driver for RTX 50. I removed the OpenCL testing code from MultiPar GUI. When it becomes 64-bit in future, I may restore the tester. I uploaded the latest MultiPar.exe on github's alpha version directory. The option item (Enable GPU acceleration) is always selectable now. It will call par2j64.exe on 64-bit OS. Please test the behavior. If you want to confirm GPU usage, you may enable log or something hardware monitoring tool. MultiPar GUI doesn't show a GPU is used or not actually.

[betagitman]

Yes, even if I had to manually enable it, now it works, it looks faster than before, I am still testing it

[Slava46]

When it becomes 64-bit in future

It would be nice.

[betagitman]

a 8GB file, with 3000/3004 blocks and 276 recovery blocks, the bar looks green with a very small yellow color at the end, it says "Ready to recover using 4 recovery blocks", I think it will be ok, I start the recovery process but it fails at 85.5% Error checksum mismatch, recovered input slice 468 (after 0:21 seconds)
I do again the repair and fails at 90.4% same error 'checksum mismatch, recovered input slice 468'
the third time fails at 89.5%, the fourth fails at 88,6% very strange behaviour, I will try with different files. Usually failure happens with BIG files. Unfortunately I cannot switch video cards because it is a remote computer. EDIT: I disabled gpu acceleration from multipar, same file 2999/3000 blocks and 276 recovery blocks "Ready to recover using 5 recovery blocks" (with gpu it was 4 blocks) and it fails at 81,2% Error: checksum mismatch recovered input slice 468. If I redo the repair, it fails at diffferent % but same input slice 468. Very strange!!!

[Yutaka-Sawada]

If I redo the repair, it fails at diffferent % but same input slice 468.

A calculation error occured, while recovering the input slice. The number 468 is the index of a lost block. After recovering lock blocks, it tests checksum of them. If checksum is different, something error happened in calculation. It's difficult to say what is the error.

Mostly there is a hardware problem, such like DRAM module or CPU's cache memory. You may see someone posted this checksum error ago at issue #148 "checksum mismatch, input file 14". I'm hard to solve this problem from software side. You may test the PAR2 files by Anime Tosho's tools. They are High performance PAR2 create client for NodeJS or speed focused par2cmdline fork. They can detect hardware errors as same as MultiPar.

[betagitman]

Yes, you were right: I had problems with my DRAM MODULES, actually 2x16GB modules Corsair CMK32GX4M2B3000C15 with a motherboard that was set with XMP configuration. (2666 was the motherboard max frequency and it accepted 3000MHz, but only with overclock). I spotted the problem with this Memtest64.exe, a good program that detected the faulty ram, so I had to order new chips and replace the chips with a 2x8GB HYNIX single side chips 2666MHz and everything now works. It was a tough work also because I had to ask a friend of mine with no computer experience to do all the dram upgrade. Once solved the problem, I bought another NVIDIA 5060ti 16GB for this computer, too because it is powerful but not power-hungry (~90W idle without monitor). Now I can run tests locally if you need to test this video card.