Fri, 13 Dec 2002 17:45:28 -0600
On Fri, 13 Dec 2002 15:20:52 -0800
"Chuck Ferring" <firstname.lastname@example.org> wrote:
> I noticed that watching live TV uses 95-100% CPU time using mpeg4
> encoding at 640 X 480. My system is an Athlon XP 1800 with 256M PC 2100
> ram. Running hdparm tells me that my hard drive throughput is about 23
> Mb / sec. Is this performance about what I should expect? If so, what
> would be the best way to increase performance, more memory, faster
> processor or faster hard drive?
MythTV when running at 640x480 with mpeg4 is almost totally
compute bound. About the only time I see any i-o problems
is on ide machine using RTjpeg since the data rates go way up.
As an aside:
640x480*29.97 fps * 24bit = 27mb/s
So tvcard -> memory = 27mbs
So memory -> agp = 27mbs
So cpu -> disk = .5 mbs
+ system overhead/compression overhead....
Just remember that VIA PCI throughput isn't all that great
so try to avoid saturating it.
-Monty Walls (email@example.com)
- MIS, Oklahoma Tax Commission
- My opinions are my own, my employer knows nothing about it.