The Intel 845GE

DDR 266 and 333 (PC2100 and PC2700). It’s the only chipset in the 845 series (including 845 845G, 845GV and 845GL) that doesn’t support SDR/PC133. You might be confused by the way you memory is reported as DDR-SDRAM. This is because DDR is an SDRAM type, i.e. the full name for DDR is Double Data Rate Synchronous Dynamic Random Access Memory. This is as opposed to older PC133 and slower SDRAM, more recently dubbed SDR (Single Data Rate) to avoid confusion.

As I said, CPU-Z will try to discover your graphics interface, but it does this in reverse; it identifies your graphics card, then how it is connected. In your case, you’re most likely using the Integrated Graphics that all the 845G-series inherit. This of course, does not have a graphics interface, because it is integrated into the Northbridge. But we can tell from this, that you should have an AGP 2.0 slot (2X/4X). Although this is not a newer 3.0 (4X/8X) slot, you’re actually quite lucky in that a 4X slot supports older 2X cards, and all AGP 3.0 cards support 4X mode. AGP 3.0 (8X) on the other hand, doesn’t support 2X cards (unless specifically modified to do so by the manufacturer, which is rare).

Now to answer your original questions

Graphics Card:
Your system can take any AGP card on the market today. I’m guessing your CPU is probably a bit old now though. Your chipset supports 400/533 MHz FSB, which gives you a maximum CPU frequency of 3.06 GHz. Commonly, people with this age chipset have 2.4 GHz. This would mean that if you bought a very high end graphics card, your CPU would be a serious bottle neck. I would recommend something in the Radeon 9800-series or GeForce FX 5900-series. Although these may be harder to get hold of today, anything faster will likely be wasted.

RAM:
You can get 2*512MB DDR, and it will work fine. Although your system supports a maximum speed of DDR333/PC2700, you can still buy and install DDR400/PC3200; it will simply select a slower speed to run at, with the added bonus of superior latencies. DDR400 is often cheaper than DDR333, which is more difficult to obtain.


I hope that answered your questions sufficiently.