I want to test the memory of my video card because there are vertical lines on my screen. I have done some basic troubleshooting and it seems that the problem is in the video card. I want to validate that the issue is the video card by testing its memrory. I have found software that is used for Nvidia cards with CUDA support, but my card is the Nvidia GeForce 7600, which has no CUDA support.
I've used the creatively-named Video Memory Stress Test app a handful of times while twiddling my video card's VRAM speeds. Unlike g80memtest, it doesn't make use of CUDA (though it can!) and should work fine for your card. Like standard Memtest, a couple of hours should be sufficient to see if it actually is your VRAM causing the problem, or something else.
If VMST doesn't find any issues, you could also try FurMark, which is an extremely intense shader processor load. It doesn't provide any feedback as to whether or not there are any rendering errors, but if your artifacts intensify or if your system crashes, then it's almost definitely a sure sign of faulty hardware.
For this type of scenario, I've previously had good results with SiS Software's SANDRA product, which conducts benchmarking and diagnostic tests on all parts of your computer, including video card tests. There is a free version, but this will only give basic information.
For more product information, see: http://www.sisoftware.net/?d=news&f=2010_release&l=en&a=
Tried VMT too on Radeon R9 290 card, but couldn't test memory above 1.5 Gb and GPU-Z utility gave me some strange readings about VRAM usage (about 250 Mb used during the test, while there should've been more than 1.5 Gb). Also it reported a crystal clean results on a definitely faulty card (it was artifacting right at the desktop before and during the test), which makes me think it doesn't actually test anything on modern cards.
So I've decided to try OpenCL: https://github.com/ihaque/memtestCL
Also, for NVidia card there is MemtestG80 tool: https://github.com/ihaque/memtestG80
Sadly, your card doesn't support OpenCL or CUDA, so there doesn't seem to be an easy way to distinguish VRAM and GPU errors. Maybe some open-source video drivers or custom firmwares may give a clue.