The LE suffix only applies to the FX 5600 and 5700. "XT" applies to the 5700 and the 5900.
- LE models have a 64 bit memory bus (most but not all), so half of the vram pads are unpopulated or they are low profile cards. For normal size cards you can tell from the presence of empty memory pads on the PCB. They're budged boards. Leadtek is an exception, since they make a 128 bit FX5700LE. Apart from the smaller memory bus, LE versions are clocked a lot lower then XT or Ultra versions. In case of the 5700, LE cards run at 275 or 300Mhz, with vram running at 400 to 500Mhz
- XT denotes the "regular" version. For the 5600 and 5700, you have an LE (budget, 64 bit memory interface, slow ram), XT - "regular" version with 128 bit memory bus using either cheaper ram or midrange ram, but this depends on the manufacturer and / or revision of the card. For example Leadtek makes a 5700XT (A360) with either BGA DDR clocked at 600MHz (TDH model) or regular TSOP ram clocked at 500MHz (TD model). Both are 5700XT's. There's also a A360 Ultra model witch also uses BGA ram, covered by heatsinks - it has a larger PCB and some versions have a 4 pin molex power connector. The ram on the ultra version is clocked at 900MHz. Core clock for the XT versions ranges from 350 all the way up to 475MHz.
- VE is an ASUS thing as far as I know. After the driver is installed the card will show up as an LE, because that's what it is. That means they're usually 64 bit and are clocked low.
The FX5500 is a slightly higher clocked FX5200, but where the 5200 can be 64 or 128 bit (the memory interface), the FX5500 is usually 128 bit. They're budget cards. Unlike the Radeon 9500 and 9550 witch are based on the Radeon 9700 and 9600 respectively and have more pixel and vertex shaders then the 9000 / 9200, the 5500 has an identical core configuration to the 5200 - 4/1/4/4. The FX5700 for example has two more vertex shaders.
Here are some pics to help you identify cards by pictures:
FX5600 / 5700 LE or VE with 64 bit memory interface. Notice the empty memory pads:
All low profile versions have 4 memory modules - two on the front and two on the back - so 64 bit memory interface. They look like this:
Typical FX5700XT with 128 bit memory - notice it has 8 memory modules unlike the LE versions that only have 4 modules
The leadtek 5700XT has 4 modules on the front and another 4 on the back, and it's not the only 5700XT like this. It's a good idea to ask for pictures of both sides of the cards. This applies to the 5600 as well.
Ultra versions have large coolers on the GPU, sometimes covering the memory modules as well. The memory modules are usually BGA (small, square) and almost always covered by heatsinks. Ultra models also have larger PCB's and an auxiliary power connector:
