Turning an old Dimension 5000 into a HTPC, what's the bottleneck?

[Thrackan]

My GF and I have been using her old PC as a "media center" for a while now, but it's lacking a bit of punch to play full HD movies. Now I'm wondering what part would be holding it back? I know about bottlenecks in games and such, but media playing is not my expertise

approx. specs (not at home atm):

Pentium 4 3 Ghz-ish
Geforce 8500GT/GTO
Not sure about the amount of RAM, I believe 1,5-2GB

Windows XP, latest Geforce drivers as of couple of weeks ago, same for CCCP Codec Pack

The PC is connected to a 32" Samsung LCD TV using 1366*768 resolution (the TV's native res).

I used XBMC and MPC-HC to test playback of a 1080p movie, both were stuttering, and I have seen this on a couple of 1080p sources unfortunately.
CPU usage is fairly high, around 50% sometimes.

I'm looking at the lowest cost upgrade, and my first guess was that a 3XXX series Radeon would help, but I've started to doubt whether that is the actual bottleneck here.

[Zyon]

Usually the lower performance graphic card is, the more work has to be done by the CPU to decode, 8500GT was (discontinued) a budget card so you can probably imagine.

Also I don't think HD3xxx or even 4xxx series are being made anymore, try the HD5450, it's small, runs cool and doesn't need extra power attached to it (silent edition is also available which have no noise level), although I wouldn't try to play games with it. (and it's cheap, only $30-35 in Australia)

[Batou1986]

U should be ok if you enable DXVA in CCCP that should make the 8500gt do most of the work.
The cpu definitely cant handle 1080p on its own.

[entropy13]

It's the Pentium 4 that's holding it back. The 8500GT is still a quite capable card.

[aCid888*]

Originally Posted by entropy13

It's the Pentium 4 that's holding it back. The 8500GT is still a quite capable card.

+1 to this.



Certainly the CPU and not the GPU.

[Mussels]

so many people fail to understand that without DXVA (or an equivalent such as coreAVC using CUDA), the video card has NOTHING to do with movie playback. by default its always rendered on the CPU.

that 50% CPU usage you're seeing when its stuttering, is one of its threads maxing out on a single threaded decoder.


for smooth 720p playback a pentium 4 can handle it if setup properly (see the guide i wrote, i think link is still in my sig) - but for 1080, you are going to need a better CPU (2.2Ghz core 2 duo or above), and/or DXVA.

note that while DXVA will work on the 8500GT and give you a performance boost, it wont work on all files - i really suggest you look into using media player classic (MPC-HC) (edit - you are, with CCCP) and CoreAVC, as its cuda decoding works on more files than DXVA (for example, DXVA is broken on MKV files with subtitles, or if they're encoded the wrong way)

[b82rez]

I'm not an expert on this stuff, but I'm pretty sure down-scaling a 1080p movie on a 720p signal makes the computer work much harder... Do you really need to watch 1080p movies if your TV can only output 720p?

[Jetster]

Sell it and build a new one

[Thrackan]

Originally Posted by Zyon

Usually the lower performance graphic card is, the more work has to be done by the CPU to decode, 8500GT was (discontinued) a budget card so you can probably imagine.

Also I don't think HD3xxx or even 4xxx series are being made anymore, try the HD5450, it's small, runs cool and doesn't need extra power attached to it (silent edition is also available which have no noise level), although I wouldn't try to play games with it. (and it's cheap, only $30-35 in Australia)

I can easily get my hands on one of these second hand for near nothing, but as I mentioned I'm not sure whether that will actually fix the problem.

Originally Posted by Batou1986

U should be ok if you enable DXVA in CCCP that should make the 8500gt do most of the work.
The cpu definitely cant handle 1080p on its own.

Originally Posted by entropy13

It's the Pentium 4 that's holding it back. The 8500GT is still a quite capable card.

Which is kinda weird when you I about it. What's the magic instruction set that makes a Core series CPU with half the clockspeed able to handle 1080p where P4's fail?

Originally Posted by Mussels

so many people fail to understand that without DXVA (or an equivalent such as coreAVC using CUDA), the video card has NOTHING to do with movie playback. by default its always rendered on the CPU.

that 50% CPU usage you're seeing when its stuttering, is one of its threads maxing out on a single threaded decoder.


for smooth 720p playback a pentium 4 can handle it if setup properly (see the guide i wrote, i think link is still in my sig) - but for 1080, you are going to need a better CPU (2.2Ghz core 2 duo or above), and/or DXVA.

note that while DXVA will work on the 8500GT and give you a performance boost, it wont work on all files - i really suggest you look into using media player classic (MPC-HC) (edit - you are, with CCCP) and CoreAVC, as its cuda decoding works on more files than DXVA (for example, DXVA is broken on MKV files with subtitles, or if they're encoded the wrong way)

I forgot CoreAVC this time 'round (been through your excellent guide before). Will look into it and see if that helps.

Originally Posted by b82rez

I'm not an expert on this stuff, but I'm pretty sure down-scaling a 1080p movie on a 720p signal makes the computer work much harder... Do you really need to watch 1080p movies if your TV can only output 720p?

Well, basically, I just have a lot of sources, and some happen to be 1080p. I want to play all of them.

Originally Posted by Jetster

Sell it and build a new one

Thanks for your constructive comment. Now, can you tell me how the 50 bucks I can get from selling an old P4 will get me a brand new HTPC?

[kciaccio]

Thanks for your constructive comment. Now, can you tell me how the 50 bucks I can get from selling an old P4 will get me a brand new HTPC?[/QUOTE]

http://www.google.com/products/catal...ed=0CF8Q8wIwAQ

It will use 1 tenth the power, it is 1 tenth the headache of a HTPC and will do a MUCH better job at the task. Trust me on this.

[cdawall]

see if the board supports Pentium D's and snag a PD965 or something they were cheap online and should decode 1080P fine my old PD930@3.2ghz does it just fine with a low profile 8400GS

[Thrackan]

Originally Posted by kciaccio

http://www.google.com/products/catal...ed=0CF8Q8wIwAQ

It will use 1 tenth the power, it is 1 tenth the headache of a HTPC and will do a MUCH better job at the task. Trust me on this.

I already have a media player. I also want to be able to stream from various websites and such, so I need a HTPC for that.

[entropy13]

Specs

[Jetster]

Dell motherboards in that series are very limited. They only support and few chips and all in the p4 800 FSB range 2.8 to 3.4 or 533 2.2 to 2.6 I believe. Ive tried to do exactly what your doing and spent too much time and money and had poor results. Hence my suggestion. It will work as a HTPC but im afraid it will only play HD for a few seconds before it stutters.

Doesn't anyone think the main problem could be the 1.5-2gig of memory. I had the same issues on a Q950 with 4gig. I upgraded to a 4850 and it didn't improve. I doubled the memory and still had some problems but it basically worked.

This was a while ago some that may not be exactly accurate, but I think it's close.

*******EDIT******** In first line that should be Q9450. It was NOT an i7-950. Apologies.

[Thrackan]

Originally Posted by twilyth

Doesn't anyone think the main problem could be the 1.5-2gig of memory. I had the same issues on a Q950 with 4gig. I upgraded to a 4850 and it didn't improve. I doubled the memory and still had some problems but it basically worked.

This was a while ago some that may not be exactly accurate, but I think it's close.

I could test that, we have another PC with DDR2 which I could plunder for a minute

[Mussels]

Originally Posted by twilyth

Doesn't anyone think the main problem could be the 1.5-2gig of memory. I had the same issues on a Q950 with 4gig. I upgraded to a 4850 and it didn't improve. I doubled the memory and still had some problems but it basically worked.

This was a while ago some that may not be exactly accurate, but I think it's close.

*******EDIT******** In first line that should be Q9450. It was NOT an i7-950. Apologies.

no, i've played 1080p (15GB files) on an XP machine with 512MB of ram before without issue. its always either CPU power, or software setup (for example, using a 2D overlay instead of 3D rendering mode in MPC-HC, can drastically boost performance on intel IGP's due to disabling aero)

Originally Posted by Mussels

no, i've played 1080p (15GB files) on an XP machine with 512MB of ram before without issue. its always either CPU power, or software setup (for example, using a 2D overlay instead of 3D rendering mode in MPC-HC, can drastically boost performance on intel IGP's due to disabling aero)

I was using GOM Player. May have also tried VLC.

[bostonbuddy]

Make sure your using MPC-HC. Used to use VLC which renders media w/ the cpu and my old htpc couldn't handle HD. Handles HD no prob w/ MPC-HC and thats w/ a 9800gt(so not much over your 8800gt)

[cdawall]

Originally Posted by bostonbuddy

Make sure your using MPC-HC. Used to use VLC which renders media w/ the cpu and my old htpc couldn't handle HD. Handles HD no prob w/ MPC-HC and thats w/ a 9800gt(so not much over your 8800gt)

nothing of the 8800GT in fact seeing how they are the same card

[Thatguy]

Originally Posted by Thrackan

My GF and I have been using her old PC as a "media center" for a while now, but it's lacking a bit of punch to play full HD movies. Now I'm wondering what part would be holding it back? I know about bottlenecks in games and such, but media playing is not my expertise

approx. specs (not at home atm):

Pentium 4 3 Ghz-ish
Geforce 8500GT/GTO
Not sure about the amount of RAM, I believe 1,5-2GB

Windows XP, latest Geforce drivers as of couple of weeks ago, same for CCCP Codec Pack

The PC is connected to a 32" Samsung LCD TV using 1366*768 resolution (the TV's native res).

I used XBMC and MPC-HC to test playback of a 1080p movie, both were stuttering, and I have seen this on a couple of 1080p sources unfortunately.
CPU usage is fairly high, around 50% sometimes.

I'm looking at the lowest cost upgrade, and my first guess was that a 3XXX series Radeon would help, but I've started to doubt whether that is the actual bottleneck here.

See if the bios will allow you to disable Hyperthreading. Give that a try.

[Mussels]

Originally Posted by Thatguy

See if the bios will allow you to disable Hyperthreading. Give that a try.

HT helps a large amount with this kind of decoding, assuming he's using a multithreaded decoder. with HT on, my 1.6GHz atom can decode 720p files (~1.1GB size) flawlessly

[Thatguy]

Originally Posted by Mussels

HT helps a large amount with this kind of decoding, assuming he's using a multithreaded decoder. with HT on, my 1.6GHz atom can decode 720p files (~1.1GB size) flawlessly

actually hyperthreading on the old P4's cuased huge performance bottlenecks and it had a high missrate and cuased cache and decoder flushs, the behavior he is describing is very symptomatic of premption cache flushing. disabling HT will resolve this issue if thats the case and the test is very simple.

[Mussels]

Originally Posted by Thatguy

actually hyperthreading on the old P4's cuased huge performance bottlenecks and it had a high missrate and cuased cache and decoder flushs, the behavior he is describing is very symptomatic of premption cache flushing. disabling HT will resolve this issue if thats the case and the test is very simple.

i tried it on the later ones (3GHz+) and it worked better for me with FFDSHOW-MT on than off, but fair call i didnt check what model P4 he has.