Which model exactly, since there are 14 different SKUs from MSI.
MSI Afterburner shows high vram and core clock usage
Well, it is either due to the GPU, CPU or OS.
GPU is actually decent. Good enough for ~60 FPS 1080p gameplay. CPU is way too old and obsolete. And OS is even worse off, since it is both outdated and obsolete as well. Win 7 support ended 9 years ago. So, why you haven't moved on to Win 10?
Any system that can run Win 7, can run Win 10 too. Or switch to any GNU/Linux distro.
But the worst off is PSU. A complete crap of a unit. It's a miracle that it still, somehow works.
I'd replace the PSU ASAP.
Good PSUs to go for, are: Seasonic Focus/Vertex/PRIME, Corsair RMx/RMi/HXi/AXi, Super Flower Leadex Gold/Platinum/Titanium.
550W unit will do just fine. 650W unit wouldn't hurt either.
(My 3x PCs are also powered by Seasonic. I have 2x PRIME TX-650 units and one Focus PX-550 unit. Full specs with pics in my sig.)
Going with completely new system would benefit too since CPU and MoBo are 12 years old (and can die at any given moment, especially when powered by that firecracker of a PSU). Less headache and more satisfaction this way.
Given that you're running 9 years outdated OS + crap quality PSU, i'd say anything is possible.