Tuesday, March 3, 2009

Smoke and Mirrors - 4870 vs 4850

Comparing the 4850 vs the 4870, which card is best for you.

If you look at the stream processors you see 800 for both cards. So you begin to ask yourself what am I paying 50% or more for?

Lets look at some NewEgg specs:

GIGABYTE GV-R485OC-1GH Radeon HD 4850 1GB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail

  • Chipset Manufacturer: ATI
  • Core clock: 700MHz
  • Stream Processors: 800 Stream Processing Units
  • Memory Clock: 1920MHz
  • DirectX: DirectX 10.1
  • OpenGL: OpenGL 2.1
  • HDMI: 1 via Adapter
  • DVI: 2
  • Model #: GV-R485OC-1GH

GIGABYTE GV-R487D5-1GD Radeon HD 4870 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail

  • Chipset Manufacturer: ATI
  • Core clock: 750MHz
  • Stream Processors: 800 Stream Processing Units
  • Memory Clock: 3600MHz
  • DirectX: DirectX 10.1
  • OpenGL: OpenGL 2.1
  • HDMI: 1
  • DisplayPort: 1
  • Model #: GV-R487D5-1GD
The only real difference here is the memory clock. In actuality both are clocking at 900Mhz. The DDR3 is double data rate which translates to 1800Mhz and the DDR5 is quad data rate at 3600Mhz. The 4870 core clock is slightly higher as well. All of this translates into about a 25% performance boost at most.

Finally we have to consider the power consumption which translates into heat. Can your case handle the extra heat? Is the 12v rail on your power supply rated to match the power consumption of the card. I recommend 25amps on that rail minimum. If your using 2 separate rails you can add them together. The 4870 uses much more power to operate.

If you're looking for stability (MMO gaming for example) you're going to want to go with the 4850.
If you're looking to get a bit more performance then pay the extra money but in most cases you will never see the difference even at higher resolutions. If you wanted to get the best of both worlds you might be able to put together a 4850 x2 crossfire system for slightly more than a 4870 but you will see huge performance gains by comparison.