RE: Dell T3500 Upgrading FAQ
Thank you for this! I recently grabbed a T3500 for $72 shipped. I sold the 2 4gb sticks, W3520 and Quadro graphics card that was in it and picked up a W3565 for $10 and 6 1GB sticks for $15. I am awaiting an HD 7870 I paid $31 for that has glitched graphics when hot. I hope to revive it as my goal was to see what kind of gaming machine could be put together for around $100. While waiting for the HD 7870 I put in an RX 460 I have since the performance should be similar. I can't believe how well it runs things and scored higher in Firestrike than I would have guessed.
P.S. Your RAM error message was due to non-matching sizes in each slot. The T3500 only likes the same size sticks set up in 3's or 6's because of the tri-channel memory setup.