Potential discovery about ATI Radeon Mobility x1300

[Knocks]

I wanted a low-heat solution for my new laptop that could still pull off Vista Aero and ordered an ATI Mobility x1300 which comes with 128MB (as opposed to the x1400 which comes with 256MB, at least those are the versions Dell sells). The x1300 did the trick and performed like a champ in Vista, and even played HD video without stuterring.

Well, I recently installed OS X 10.4.8 on this machine, and what do you think I see in System Profiler?

Type: Display
Bus: PCIe
VRAM (total): 256 MB
Vendor: ATI (0x1002)
Device ID 0x7149

Hah! The same card reported 128MB in Vista. Could both the x1300 and x1400 have the same amount of RAM, but only activated through software? These cards are not officially supported by OS X, so maybe the extra RAM became unlocked through an unofficial driver? I am tempted to take the card out and look at the amount of physical memory on it.

 

[postmortemIA]

same core, different BIOS.

 

[MercenaryForHire]

http://ati.amd.com/technology/hypermemory.html

- M4H

 

[Knocks]

Originally posted by: MercenaryForHire
http://ati.amd.com/technology/hypermemory.html

- M4H

Are you saying it's reporting an extra 128MB of virtual RAM? So it's actually hogging up 128MB of my system memory? Does that mean the x1400 would be reported as 512MB?

 

[aka1nas]

It's hypermemory, which is ATI's PCI-E based memory sharing tech. It only uses up system memory when it needs it. It's not hurting anything.

 

[Knocks]

I did some research on this. ATI Hypermemory doubles the amount of on board memory by borrowing the other half from system RAM. So if a card is advertised as 128MB, it has 64MB physical RAM and 64 shared RAM. The x1300 in question is advertised as a 128MB card but is reported to have 256MB by OS X. That leads me to believe that it's actually the same card as the x1400.