Radeon HD 4855 

Released January, 2010
  • 575 MHz
  • 512 MB GDDR5

Features Key features of the Radeon HD 4855

memory bandwidth Rate at which data can be read from or stored in onboard memory

Radeon HD 4855
115.2 GB/s
Radeon HD 7770
72 GB/s
Radeon HD 8670
73.6 GB/s

pixel rate Number of pixels a graphics card can render to the screen every second

Radeon HD 4855
9.2 GPixel/s
Radeon HD 7770
16 GPixel/s
Radeon HD 8670
8.4 GPixel/s

texture rate Speed at which a graphics card can perform texture mapping

Radeon HD 4855
18.4 GTexel/s
Radeon HD 7770
40 GTexel/s
Radeon HD 8670
25.2 GTexel/s

floating point performance How fast the gpu can crunch numbers

Radeon HD 4855
Radeon HD 7770
1,280 GFLOPS
Radeon HD 8670
806.4 GFLOPS

shading units Subcomponents of the gpu, these run in parallel to enable fast pixel shading

Radeon HD 4855

texture mapping units Built into each gpu, these resize and rotate bitmaps for texturing scenes

Radeon HD 4855

Specifications Full list of technical specs


GPU brand ATI
GPU name RV770
Market Desktop
Clock speed 575 MHz
Is dual GPU No
Reference card ATi Radeon HD 4855 575 MHz 512 MB

raw performance

Shading units 640
Texture mapping units 32
Render output processors 16
Compute units 8
Pixel rate 9.2 GPixel/s
Texture rate 18.4 GTexel/s
Floating-point performance 736 GFLOPS


Memory clock speed 900 MHz
Effective memory clock speed 3,600 MHz
Memory bus 256 bit
Memory 512 MB
Memory type GDDR5
Memory bandwidth 115.2 GB/s

noise and power

TDP 110W
Report a correction


comments powered by Disqus