WOW! {Or Holy whatever}

[Gary Kline]

On Thu, May 10, 2007 at 05:23:17PM +0100, Tom Evans wrote:
> On Thu, 2007-05-10 at 08:49 -0700, Garrett Cooper wrote:
> > A good rule of thumb: Don't buy a video card with more RAM than 1/8 to 
> > 1/4 of the system RAM, because the RAM is shared with the system RAM, 
> > which means you have less overall system RAM to use for apps.
> > 
> > -Garrett
> 
> Er? Whilst I agree with the sentiment (low end graphics cards with 512MB
> of RAM are solely there to rip off the unwary), that is complete tosh.
> 
> Some cards dont have much/any onboard dedicated RAM; instead they use
> system memory. Examples of these are nvidia cards labelled 'TC' (Turbo
> Cache), most (all?) integrated intel video chipsets.
> 
> The other issue is on i386. 32-bit systems have 4GB of address space to
> use. Since you want to be able to address the graphics cards memory,
> some of this address space is allocated so the OS can address the
> memory. This means that if system RAM + video RAM > 4 GB, some of the
> system RAM is unaddressable. That itself is a bit simplistic (its not 4
> GB, its ~3.5 GB, for various reasons.)
> 
> The main point is that if you have a system with 1 GB of system RAM and
> put in a graphics card with 640 MB of video RAM, you still have 1 GB of
> system RAM to play with, even though you have gone over 1/4 of the
> system RAM.
> 

	Urk! Can you hear the flip-flops spinning in my brain? Ok, once I
	have figuredout what is in Garrett's Dell I'll know if I even 
	_want_ to spring for a new card.   Assuming YES and assuming I
	look for an ASUS 6200: is it an AGP?  128M seems way overkill,
	but if the ASUS doesn't cheap-out and use system memory, I'd be
	happy.

	What say?

	gary


> Tom



-- 
  Gary Kline  kline at thought.org   www.thought.org  Public Service Unix