Worth upgrading RAM from 8 to 12 for intell hd4000 ?

[iiinsane]

I recently purchased a vaio laptop with 3rd generation i3 processor and hd4000 graphic card. It came with 4gigs of ram. I increased the ram to 8 gig with spare I had from my old laptop. It produced a huge improvement on performance. I went from getting 21 fps on grid2 (game) to 35 fps. What I wonder if I can expect to see more improvements if I swap one of the 4 gig sticks for an 8 gig stick for a total of 12 ram. Or is there a limit and it won't improve much after 8 ?
Any advise much appreciated.

 

[jaguarskx]

The reason why you noticed the large improvement in performance is probably because you only had 1 stick of RAM. Doing so basically doubled your memory bandwidth. Having just one stick of RAM means your RAM is operating in single channel mode, or half the maximum bandwidth. Having 2 sticks means RAM will be operating in dual channel mode.

Since the Intel HD 4000 uses system RAM, the doubling of the memory bandwidth has increased the HD 4000's performance. Increasing it to 12GB or 16GB will likely not make any difference.

 

[iiinsane]

Oh, I thought it was the amount, before I got another 4GB stick I tried a 2GB for total of 6GB and it increased by fps by 7, so when 4 to 8GB gave me 14fps, I figured 7fps per 2GB.

Thanks for the quick reply

 

[jaguarskx]

It is possible that the additional RAM also meant that more of it is allocated to the Intel HD graphics core. For example, with only 4GB of RAM only 128MB could be allocated to the Intel HD 4000, 6GB could mean 256MB, and 8GB could mean that a total of 512MB has been allocated to the Intel HD 4000. I am just making up those numbers since I do not know how Intel's dynamic RAM works and I don't know what the maximum amount of RAM that can be allocated to the Intel HD 4000.

Having 12GB could mean 768MB will be devoted to the graphics core. However, the BIOS in the laptop can also override whatever maximum limitations Intel imposed. By override I mean a lower maximum. For example, I remember someone complaining that with his particular laptop make and model, only a maximum of 256MB of RAM was allocated to the Intel HD 4000 even though he had 16GB of RAM.