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When doing screen recording, I can get a frame rate of maybe 15 frames per second for the full screen on my 1080p monitor using the XVID codec. I can increase the speed a bit by recording a region, changing screen modes, and tweaking other settings, but I'm curious what hardware upgrades might give me the biggest bang for my buck.

My PC is budget, but modern...

  • Athlon 2 X4 645 (3.1GHz, quad core, limited cache) processor.
  • 4GB single channel DDR3 1066 RAM.
  • ASRock motherboard with NVidia GeForce 7025/nForce 630a Chipset.
  • ATI Radeon HD 5450 graphics card - 512MB on board, not configured to steal system RAM.

I dual-boot Windows XP and Windows 7. For the moment, XP is my bigger performance concern as it's still my getting-things-done O/S as opposed to my browser-host O/S.

My goal is to make a few programming-related tutorials. For a lot of that I don't need screen recording - I can make up some slides, record audio with the PC switched off, yada yada. When I do need screen recording, I'll mostly be recording Notepad++, Visual Studio or a command prompt. Occasionally, I may be recording some kind of graphics or diagram program and using my pre-Bamboo cheap Wacom tablet - I have the CS2 versions of Photoshop and Illustrator, but I'd much more likely be using Microsoft Paint. Basically, what I'll be recording won't be making huge demands on the machine - but recording a fair number of pixels (720p preferred) will be useful.

What's particularly wierd - not so long ago I still had a five-year-old Pentium 4 based PC. And (with the same 1080p monitor) it could record at not far from the same frame rate. So clearly the performance issues are more subtle than just throw-money-at-it.

My first guess would be that the main bottleneck is the bandwidth for transferring data to/from the graphics card. Is that likely to be correct?

  • In support of that, see this [Radeon HD 5450 review][1] - the memory bandwidth is only 12.8 GB/s. If you can't get data out of graphics memory quickly, you can't transfer it back to the system memory quickly. Apparently, that's slower than some top-end cards in 2002.
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closed as not constructive by studiohack Nov 15 '11 at 2:23

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Have you looked at disk I/O as a bottlneck? Do you have more than one drive? – Dave M Nov 13 '11 at 20:49
@Dave - one Hitachi 1GB drive and one Western Digital 500MB drive. SATA2 rather than SATA3, but that should still be more than enough. And there's very little disk activity when recording. – Steve314 Nov 13 '11 at 20:56
other options - get a soild 15fps going, work meticulously, change the frame rate later to 30fps 2X (which doesnt nessisarily require re-encoding) then voice over the whole thing meticulously. On the older stuff it is interesting to note that 2D speeds have gone to heck over time , while they concentrate on 3D speeds. it is entirely possible that an old 2D only matrox card from the 90s can actually do directx 2D much faster. they left 2D speed in the dirt. – Psycogeek Nov 13 '11 at 21:58
@Psycogeek - interesting point about 2D performance. A lot of desktop 2D graphics are now accelerated by the 3D hardware in Win7 but that's not the case in XP. I guess I'll have to do some tests in Win7. On the other stuff, yeah, slightly stuttery video isn't that terrible anyway. I don't know what quality frame-interpolation is possible, but it's probably not needed anyway - just fill in with duplicate frames. It would still be nice if I can get everything smooth - not necessary, but nice. If the trade-off is more cooler-noise in the audio background though... – Steve314 Nov 13 '11 at 22:17
@Psychogeek - "stuttery" may not be what I meant. A slow frame rate is usually OK for a tutorial, whereas an inconsistent frame rate can be very distracting. – Steve314 Nov 13 '11 at 22:28

It looks like the main bottleneck was the software.

I thought I'd have a look back through utilities I'd saved from old magazine cover disk deals. I found version 1.5.3 of BB Flashback Express (definitely from PC Plus) and version 3.0 of TechSmith Camtasia (not Studio, and probably from PC Plus too, though I'm not sure). I also Googled for other screen recorders.

One stupid thing I did was to install both v1.5.3 and the current v3.0.3 of BB Flashback Express. Something caused problems - probably conflicting versions of its "screen capture driver". It also became obvious that even after giving my e-mail address to get the free BB Flashback Express, an online regstration is needed to use it for more than a trial period. That's a problem for me.

I did get things cleaned up and a working install of the 1.5.3 version. Seems fine, and to give good frame rates, but it's not easy to check the actual frame rates. I may give the demo version of v3 another go later - I like it, I like the look of the standard versions price too, but the registration issue has me hesitating.

TechSmith Camtasia 3.0.3 is old (April 2002), but excellent. I don't know how I managed to register and then just forget this - I guess when you don't have a use at the time, it doesn't matter how good it is.

With Camtasia 3, I can get a little under 25 frames per second using the XVID codec. This is about the same as CamStudio. The difference is that with Camtasia, if I ask for 20 frames per second I get precisely 20 frames per second, not around 12 to 15, and I don't have to figure out milliseconds per frame to go with the frames per second. Camtasia and CamStudio even look remarkably similar - my guess is that one copied a lot from the other.

Using the Camtasia screen recording codec, I can get within a hair of 50 frames per second - 40fps rock solid. I can't get the camstudio codec to even work reliably - the video gets corrupted badly, I think something went wrong due to me installing 2.6beta before 2.0 or something like that, though both the 1.0 and 1.5 codecs are affected.

Another option that's still available is Microsoft Expression Encoder. The trouble with this - the free version claims to allow screen recording, but once you install it (1) you start getting demands for serials again, and (2) when you try to test it, it warns that the standard version (not even just the free version) only allows 10 minutes recording at a time. Seeing that, I immediately uninstalled without even trying it.

The current Camtasia Studio is probably outside my price range for the moment. BB Flashback Standard is looking quite tempting, though I'll have to check whether I'll still have online registration issues. For the moment, though, I'm quite glad I registered Camtasia 3 from a magazine deal - and very happy to discover there don't seem to be any license restrictions on what I can do with the videos.

Anyway, what started as a question about hardware bottlenecks seems to have turned into a comparitive review of software, and the winning product isn't even available any more. I'll notify the moderators - seems a bit off-topic, but maybe it's worth keeping some of this information around anyway.

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