Re: [9fans] image/memimage speed

["Russ Cox" <rsc@swtch.com>]

On Fri, Dec 5, 2008 at 10:27 AM, Russ Cox <rsc@swtch.com> wrote:
>> i don't think this is the case.  if you recall from the original
>> post, i have used the pat registers to set up memory types on
>> a pcie card and i do see dramatic speedups for drawing to
>> the screen.  however, reading from the screen is just as slow
>> as before.
>
> I think the problem of

I think the problem is that when video card manufacturers
optimize read bandwidth, they are working on the read bw
of the video card's RPC-like interface, not the read bw from
the video memory.

To a first approximation, no one reads directly from video memory.

Russ