pyTivo Discussion Forum

christoman · Joined: 01 Feb 2009 Posts: 3

Love pyTivo and have been running it on my P4 (3.2 GHz) for awhile. Just installed it on my HP EX470 Windows Home Server with a AMD Sempron 3400+ (1.8 GHz) which I intended to upgrade to a dual core AMD BE-2300 (1.9 GHz), thinking faster clock speed plus dual core would make a significant difference.

Yesterday, I downloaded the same 57 minute video (DivX 960X540 resolution) to my Tivo HD from both the machines and was surprised that performance was nearly identical (25.25 minutes/7.82 mb/s for the AMD and 26.7 minutes/7.19 mb/s for the P4). I expected the P4 to be faster than the AMD.

This makes me wonder if upgrading while buy me much. Is transfer speed the real gating issue? Have others found a significant difference with upgrading the CPU in real-world Tivo transfers - particularly to dual core?

Thanks - Chris

wmcbrine · Joined: 04 Jan 2008 Posts: 2010 Location: Maryland

There are TiVo-side limits, but I don't think you're running into them yet.

The P4 runs at a very high clock rate per amount of performance. If you compare that clock rate to the "equivalence number" on the AMD, they're pretty close in your case. (Nominally, the number is supposed to be the equivalent performance compared to an original Athlon running at that clock rate, but IIRC, it's been found to compare pretty well to the P4 at the same clock rate.) So I wouldn't expect the P4 to be faster, no.

The whole design of the P4 was geared towards being able to run up the clock rate for advertising purposes, not so much towards real performance. That's why Intel went back to P3-based designs for their newer chips, and why they've finally abandoned clock rate as a measure of performance.

christoman · Joined: 01 Feb 2009 Posts: 3

Thanks for the great follow-up. Have you seen that pyTivo (or ffmpeg specifically) really takes advantage of a dual core CPU?

wgw · Joined: 06 Jan 2008 Posts: 284

Yes, Dual or quad core will certainly increase your performance. I have a 3.0 P4 and it's way too damn slow. I'd buy the fastest quad I could afford if I had any money.

choekstr · Joined: 06 Dec 2008 Posts: 152

I concur. I went from a 3.2Ghz P4 to a Quad Core 2.4Ghz (Q6600) box and realized huge performance gains.

I was getting ~12 FPS with the P4 single core to around 38 FPS with the Quad Core on 720p files and about 24-25 FPS on 1080p files. Both of those are better than realtime for movies and I am extremely happy with a system upgrade.