System RAM Impact on Similar Cards

I’ve been searching the forums to find answers to two questions, but I haven’t been able to so far. I apologize if a similar post has already been made and I simply didn’t locate it.

I’ve seen some posts regarding the performance differences between different cards in the same series (i.e. 7800gtx vs. 7900gtx) with different amounts of VRAM and different amounts of system RAM. However, I haven’t found one that addresses the performance difference between two different cards in the same series that have the same amount of VRAM, but different amounts of system RAM.

For example, take two notebooks configured exactly the same, except that one has an 8600m GT w/512 VRAM and 4 GB system RAM and the other has an 8700m GT w/512 VRAM and 2 GB system RAM. Which of these two machines would handle games better?

Also, at what point does additional system RAM cease to yield any gains in terms of gaming as well as overall performance?

Any input and direction on these questions will be greatly appreciated.

Thanks

 

Go with the higher series number. The difference in video power makes all the difference in the world to games. Honestly, I haven't seen any current games that really show a noticeable performance boost with more than 2 GB of RAM. Make no mistake they are on their way, but they aren't here yet. Besides that, 32 bit operating systems can't take advantage of more than about 3 GB of RAM (for an explanation of why, see http://en.allexperts.com/q/PC-hardware-CPU-1023/Windows-XP-memory-limit.htm).

 

well apparently there is quite a large performance increase with the mobile 8xxx series, dont remmebr where i saw this though

i meant with 3 gigs of ram that post mad no sense b4

 

The 8700 will handle games better for a number of reasons not related to RAM (higher clock seeds, dual memory bus, etc). How much additional RAM will be of benefit depend on how well the game is programmed to utilize memory, and how memory intensive it is in the first place.

GenTech (aka Ken Lee) was testing the V1s and VX systems (running 8600M GT cards) and found that going from 2GB to 3GB increased VRAM to 1.5 gb and he saw a significant increase in games that demanded RAM (he noted one game jumped from 18 fps to 30 fps). He graciously said he will get one of those systems install Vista 64-bit and put in 4GB, so that information (and how much of a performance jump it provides over 2GB and 3GB systems) may be available soon.

 

I thought that TurboCache was nothing but a marketing gimmick? How can 1.5GB of system memory help with faster processing? I don't get it.