How Much RAM Does Your Graphics Card Really Need?

Three Radeon HD 4870s: 512MB, 1GB, And 2GB

Powercolor AX4870 512MD5-G Radeon HD 4870 512MB

We'll begin with the 512MB card, a PowerColor Radeon HD 4870.

Read Customer Reviews of PowerColor's AX4870 512MD5

This card is overclocked from the factory with a GPU speed of 770 MHz compared to the reference 750 MHz, so we'll lower this to the reference speed for our testing to keep everything on an even keel. The GDDR5 memory runs at 900 MHz, which is the same as the standard Radeon HD 4870 reference speed. This card retails for about $135 on Newegg.

XFX 487A-ZHFC Radeon HD 4870 1GB

Read Customer Reviews of XFX's HD-487A-ZWFC

This XFX version of the Radeon HD 4870 comes with 1,024MB (1GB) of RAM, and runs at the reference 750 MHz core and 900 MHz GDDR5 memory speeds. This model costs about $145 on Newegg.

Sapphire Vapor-X Radeon HD 4870 2GB

Read Customer Reviews of Sapphire's Vapor-X Radeon HD 4870 2GB

This Sapphire card is equipped with four times the memory of the 512MB card. While it sports the same 750 MHz core and 900 MHz GDDR5 memory speeds as the reference Radeon HD 4870, it comes with a unique aftermarket cooler. This model costs about $227 on Newegg.

Now that you've seen the contenders, let's have a closer look at the test system and move on to the benchmarks.

  • radiowars
    Great article guys. I've debated this many times with friends- good to see a definite result. Heh, GTX 275 w/ 896 works well @ 1680x1050 for me. I doubt I'd need anything higher than that for my resolution.
  • burnley14
    I really like the alternating images you use in these articles, they are very helpful and make it much easier to compare the various detail settings.

    Also, great article overall. Keep up the good work!
  • cleeve
    Thanks burnley, animated GIFs are a bit of a pain to make, but it's nice to know they're appreciated. :)
  • blueer03
    This was very interesting. But I would like to see the performance difference from a mid-stream (say a 4850) as compared to a high end video card. Would it have made sense to spring for the 1GB 4850, or would there be no difference because of the cards inherent limitations? And the same thing with the lower level cards. At what point in the hierarchy of video cards does springing for more than the reference memory levels make sense?
  • cleeve
    With lower end cards you'd see the same effect, but with the lower frame-rates that those cards would produce. The end result is the same: one they run out of RAM at a certain setting, the performance will suffer, but until then it's the same across the board.
  • knutjb
    How much ram will the 5870 eyefinity version need?
  • cleeve
    knutjbHow much ram will the 5870 eyefinity version need?
    Depends on the resolution and settings just like everything else. but it's a good question, if there's enough interest in this article I'll look into that in the future.
  • liquidsnake718
    Im surprised that Crysis doesnt utilize all the RAM(even for an older title) for distance similarly to titles like GTA. Im sure the new Crytek engine will make use of Ram so we can see even buildings and huge alien robots further in the distance with vivid details.

    We can only look forward to a more intense and visually stunning Crysis 2 as I can only imagine how the story would progress and end up being in space. I can imagine huge asteroids looking as real coming at the player using nvidias 3d vision and utilizing AA in order to make it apparent from a distance.

    Think Halo style world but with unrivaled graphics and a more realistic feel with DX11.
  • How about doing this same comparison with crossfire setups?
  • Arkz
    il tell ya whats a bitch, i have a 1920x1080 monitor, nice? yes. I have an 8800GT too.. nice? kinda.. its the 256MB version.. so.. if i wanna turn up the sexiness i get baaaad fps