Development Questions for Sub.

[SuperG]

Sub,

I have a bunch of questions that are more curiosity than requests. I have next to no programming experience so this truely is just a 'howzat work?" type of post.

1. With dual processors, Hyperthreading, and the dual core one processor almost ALWAYS sits unused. This is due to the fact that nobody writes multi-threaded applications. Why is that? Is the programming extremely complex to accomplish that? Can Software be written to be specifically run on the second processor or is that in the hands of the OS or hardware?

2. As near as I can tell there really isn't anything in GBPVR that would benefit from multi-threading but it sure would be nice to be able to offload live TV to its own processor. Can you see any theoretical advantage to this or am I missing the forrest through the trees?

Thanks for your time and efforts Sub!

[bungle]

1. With dual processors, Hyperthreading, and the dual core one processor almost ALWAYS sits unused. This is due to the fact that nobody writes multi-threaded applications. Why is that? Is the programming extremely complex to accomplish that? Can Software be written to be specifically run on the second processor or is that in the hands of the OS or hardware?

That depends on what you are doing with it. I'd be using both cores all the time if my computer at work were dual-core like my one at home (compiling, running servers, etc.) Even if an app isn't multi-threaded, you can still take advantage of a dual-core by running 2 apps at the same time. Even though each one is single-threaded, the OS can put each one on a different processor.
In general it is harder to write multi-threaded applications (especially correct ones). However, it is much easier in languages like Java and C#, which have explicit thread support. In both instances, though, the language is abstracted from the OS and hardware via the virtual machine, so ultimately it comes down to the VM and OS to properly allocate the threads to the processors.

2. As near as I can tell there really isn't anything in GBPVR that would benefit from multi-threading but it sure would be nice to be able to offload live TV to its own processor. Can you see any theoretical advantage to this or am I missing the forrest [sic] through the trees?

What do you mean by putting live tv on its own processor? I mean, GB-PVR isn't doing much else when you watch tv, so it really doesn't matter which processor it is using - one's the same as another.
I can think of a couple of things in GB-PVR that would benefit from dual-cores: comskip and MVP servers. In both cases I think these are already run as separate processes, so the OS should divvy up the work well. So comskip should run on a show on one processor while GB-PVR or whatever else you are doing is going on another. I know now that I have my dual core comskip can gobble up 100% of one CPU while I'm doing something else and I don't even notice.

[sub]

2. As near as I can tell there really isn't anything in GBPVR that would benefit from multi-threading but it sure would be nice to be able to offload live TV to its own processor.

Sure there is. GB-PVR is made up of multiple processes (recording service, front end, tray app, possibly multiple MVP servers) that can each be doing own thing at any time, so having an additional cores or CPUs available will allow more than one of these to be serviced at any specific instant.

The recording service is also made up of about half a dozen threads, each of which can take advantage of additional core and CPUs.

The frontend process (GBPVR.exe) is also made up of several threads, but defaults to limiting things to one processor core because directshow often seems to have problems with hyperthreading or dual cores, which can lead to stuttering. This is configureable though by changing the <ForceSingleProcessorAffinity>true</ForceSingleProcessorAffinity> setting to 'false' in config.xml

[SuperG]

Comskip is one of the apps I was thinking about that could run in the background without taxing LiveTV. That and ripping shows to MPEG-4 for my ipod.

I'm still a bit lost on the voodoo that is Comskip, but its on my list of things to learn.

I'm debating a Pentium D 2.66 for a dedicated PVR machine and wasn't sure if they hype was going to payoff as it never has in the past for me.

Are all the plugins written here pretty high level things or is there an equivalent "Hello World!" plugin that could be written for GBPVR so one could start learning the ropes? To make that clearer, do you really have to know your stuff to work on plugins for this or is it pretty easy to work into?

Thanks again for your time!

[bungle]

I'm debating a Pentium D 2.66 for a dedicated PVR machine and wasn't sure if they hype was going to payoff as it never has in the past for me.

Dual-cores are worth the hype, but maybe not for PVRs. If it's truly dedicated then unless you are really recording and transcoding a lot simultaneously it will probably be overkill. My dual-core is my main PC and a GB-PVR backend (with an MVP frontend), so it has to do everything. Not that the extra core won't make things nice, but you can get by with less, especially if you're not doing HDTV. It's up to you and how much money you want to invest.

[SuperG]

Well, That chip is $130 and a Single is $104, so it seemed like it was probably worth the $25.

Dunno.

[bungle]

Well, That chip is $130 and a Single is $104, so it seemed like it was probably worth the $25.

Dunno.

Wow - when I bought my AMD dual-core the difference between the single and dual was about double. For 25 bucks, though, might as well, assuming you can use pretty much the same motherboard (I know more about AMD than Intel).