Came across this interesting factoid on how Intel's and ATI's integrated video use system ram at Notebook Review
Intel's Extreme Graphics, Extreme Graphics 2, and GMA 900/950 parts all dynamically adjust the amount of memory they share from the system, taking only as much as they need at any given time. But when you're gaming, they're going to be taking all they can -- the Extreme Graphics parts will steal 64MB, and the GMA parts will steal as much as 128MB, so you can subtract that from your total amount of memory to determine how much memory is left over for the actual game you're playing.
ATI's Radeon Xpress 200M and its older integrated graphics parts (Radeon 7500/9000/9100 IGP, 320M/340M IGP) use a set amount of system memory and this does not dynamically change. It must be set in the BIOS of your notebook (see your manufacturer's site for details on how to do this). Because of this, while an Intel part which will draw as little as 8MB of system memory when not in use, the ATI part will always be drawing the same amount (usually 64MB or 128MB) from your system memory, and this can severely cripple performance.
Now that would explain it... when I went to set the video memory size on my work machine (an IBM ThinkCentre with GMA 900 video), I found it weird that I could only choose 64 or 128MB in the BIOS. Only to later check how much memory was used for video in Everest, and it said 8MB was used. I wonder why not all onboard video adjust memory like that
Core i7 2600K @ 4GHz | Noctua NH-C12P SE14 | ASUS Maximus IV GENE-Z | 16GB G.Skill Ripjaws X 1600 CL9 | Gigabyte GTX 670 OC 2GB | 256GB Crucial m4 | 2TB WD Green | Samsung DVD±RW | Seasonic X 460w Fanless | Fractal Design Define Mini | Windows 7 Ultimate | Dell 2209WA @ 75Hz
Earlier ATI IGP chipsets for notebooks (Radeon 350 or something like that, used with socket A) had BIOS option to dynamically allocate RAM as well, dont know about those produced today though. Oh and I remember I845 had the ability to specify the amount of ram allocated,but again, I dont know about GMA900.
Anyway with todays prices of ram, its really not that expensive to get 512MB or even 1GB of ram for your notebook. Latter is actually cheaper then decent 2.5" disk, which IMO is quite amazing. Laptop parts relly did go down in price.
Oh and all shared ram is capped at 128MB, have not yet heard of IGP that would use more then that.
Last edited by F_A_L_C_O_N; November 9th, 2005 at 08:51 AM.