Spentshells, no.
The FX5200 was an AGP/PCI card. The PCIe version was called the FX5300 and was SUPER rare. It's nice you say he means something, but he wrote 8x slot. While there are 8x PCIe slots, as I mentioned above they aren't common. What is common is what he wrote. He has an "8x" slot/card, and its currently running an FX5200. This means we are talking AGP here, not PCIe. While true we won't know for sure until he posts a motherboard, I find it far more likely that he has AGP over some odd PCIe slot.