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gamerz

macrumors 6502
Original poster
Oct 2, 2006
479
0
I'm not sure if this is in the right place... But on the $1349 (Canadian) imac, the ATI X1600 comes with 128mb of SDRAM, while on the $1699 model, the ATI X1600 comes with 128mb of VRAM. So, does this dfference effect gameplay while playing games like WoW? Also if it does... how much of a difference?

Thanks
 

sparkyms

macrumors 65816
Feb 22, 2007
1,304
3
Southampton UK
here's what wikipedia says about VRAM:
from Wikipedia
Video DRAM (VRAM)

VRAM is a dual-ported version of DRAM formerly used in graphics adaptors. It is now almost obsolete, having been superseded by SDRAM and SGRAM. VRAM has two sets of data output pins that can be used simultaneously.

The first port, the DRAM port, is accessed as with plain DRAM. The second port, the video port, is read-only, and is dedicated to feeding a fast stream of data to the display. To use the video port, the controller first uses the DRAM port to select the row of the memory array that is to be displayed. The VRAM then copies that entire row to an internal shift-register. The controller can then continue to use the DRAM port for drawing objects on the display. Meanwhile, the controller feeds a clock called the shift clock (SCLK) to the VRAM's video port. Each SCLK pulse causes the VRAM to deliver the next item of data, in strict address order, from the shift-register to the video port. For simplicity, the graphics adapter is usually designed so that the contents of a row, and therefore the contents of the shift-register, corresponds to a complete horizontal line on the display.
 

robbieduncan

Moderator emeritus
Jul 24, 2002
25,611
893
Harrogate
SDRAM is just a type of memory. VRAM is a short term for Video RAM which is a generic term for dedicated graphics memory (these days). iMacs that have dedicated Video RAM currently use GDDR3 SDRAM for their VRAM.

I think there is a type in the original post and the second amount should be 256Mb not 128Mb, in which as the question is do you notice the difference in the amounts of RAM. The answer to this is game specific, but in general yes: the additional RAM will allow higher resolutions to be playable at a decent frame rate as textures will have to be paged in and out of VRAM less and there will be more space for the frame buffer.
 
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