Dual G4 Performance?

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Dual G4 Performance?

I'm thinking about building a HTPC out of a Mac of some sort, and I'm wondering what the minimum speed dual processor G4 is for playback of MPEG-4 without dropping frames? I've been using Handbrake to rip my DVDs to MPEG-4 files with default settings targeting about 1000 kbps bitrate and otherwise generally 480i/p NTSC format.

Ideally, I'd like to display on an HD TV (1080p, 1920x1080). I realize that what I'm ripping isn't HD quality, but I don't care so much about that. Besides, the original source was only 480i or 480p at best anyway. But I do care about using all the available screen without dropping frames. If I have to use 720p instead, that's fine, too.

I know that my iBook G4 800 MHz can do 720p resolution upscaling of just about all my movies without dropping frames, though every now and then there is a movie which it just can't handle cleanly. I know that my VGA 667 MHz PowerBook G4 can't playback movies without dropping frames. So I was thinking maybe a Digital Audio dual 533 MHz G4 could.

Does anyone have any experience in this area? I'd love to pick up a cheap older G4 (dual 450s are dirt cheap these days), but I don't want to waste money on something that can't do what I want it to do.

What about video cards? Can a GeForce 2 MX do what I'm asking? How about a Radeon 7000 or Radeon 7500?

I'd appreciate any thoughts you guys have.

Peace,
Drew

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Upgrade Costs a Problem on G4s

I have been thinking about this too.

The problem is upgrades are Sooo expensive.

It seems like a better deal if you can get a dual G5 machine (admittedly kinda high at $650 plus on ebay) but you can use PCI express video cards (much cheaper and more capable than AGP or PCI video cards), the RAM is way cheaper, plenty of room for a cheap SATA card and big cheap SATA hard drives (I've seen 500GB drives for $55!!!)

Any upgrades to a G4 are crazy expensive and really a standard dual G5 would probably do all you need stock (only the dual G5s have PCI express).

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You are absolutely right. A

You are absolutely right. A G5 of any flavor would do everything I want right out of the box. I'm thinking even the lowliest single G5 would work fine. And upgrades for them are indeed cheaper. But a G5 is also definitely overkill. And it would be noisy as heck. I've experimented a bit with a 1 GHz B&W G4 w/ a Radeon 9200 that I've had in storage, and it's passable at 720p, but it's just a little too slow to handle what I want to do. The 66MHz system bus (the Sonnet 1GHz G4 knocks down the system bus to 66MHz) and the PCI video are dogs. Plus, the two fans on the CPU heatsink are really noisy and distract me from the entertainment.

The point is to go cheap by buying a stock machine as far down on the performance spectrum as possible. I won't be buying upgrades. Other than about a gig of RAM and possibly a video card, I won't need anything else. (I know, bad plans for future-proofing. Shh, don't tell the wife! It'll be an excuse to buy a better machine in the future and add this to my collection! Wink )

I've already got two Cat-5e lines to the TV (one for a TiVo and one for whatever other machine I've got in the entertainment center). It's currently 100base-T but I could conceivably upgrade to a gigabit router. I've also got an 11n base station (operating in mixed b/g mode because I don't have any 11n cards) that is fast enough for my iBook to play back videos from a server. Speaking of servers, I've got an MDD and a QuickSilver hosting my movie collection(s) spanned over a few TB of storage between the two. I'm using NFS automounts with an alias in the "Movies" folder of my home folder pointing to the movie folders on the NFS servers. Then when I start Front Row on any Mac connected to the TV, the movies are available for playback without requiring me to run iTunes on a remote machine (though I can do that, too). So I plan to keep using the infrastructure that I've already got in place. I won't be hosting all my movies locally on the media center Mac.

Anyway, I'm wondering where that bottom threshold is. My 800MHz iBook G4 seems to be about it. So what would be comparable in a desktop machine?

Peace,
Drew

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Something else I've been toyi

Something else I've been toying with is using a headless eMac, iMac G4, iBook, or PowerBook. I've got an old Apple Set Top Box that would be great for a case conversion for a notebook of some sort. Or I could drop an eMac logic board and DC-DC board into a Power Mac 6100 carcass for a similar effect. And then using the Keyspan Front Row RF remote (I bought three on eBay for $5 each a while back) would just be a hoot. Or better yet: I could hook up the IR receiver from a newer Mac (they are USB devices, right?), hide it behind the IR window on the STB, and run it with Apple's IR remote.

But after all is said and done, the cost of doing that exceeds the price of an older dual G4 Power Mac. Buying the bottom half of a reasonably spec'd PowerBook alone blows the budget. And then I'd still have to rig up a cooling mechanism for the case. It would be an interesting project, and probably something I'll still do in the future for giggles or for when I decide to "upgrade", but right now I'm really wanting to keep the price down.

Peace,
Drew

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I don't think you'd get suffi

I don't think you'd get sufficient speed on a dual processor lower than 800 MHz.
While I don't have video playback experience with that era of G4, I do remember from general use, the dual-450, and IIRC I may have had a dual 500 for a while, just weren't that much faster than the single processor models for most tasks. You'd need to know your playback software was able to use both processors, and even on a good day, as you know a dual won't ever give you 2X your core speed.

I do know that the original xbox with its 733 Celeron and 2 MX graphics isn't good for 1080p. That apparently changes if the processor is upgraded, so at least in that instance the 2 MX is capable.

Whichever option you choose, check out the OS X version of XBMC. I've been using XBMC (on an xbox) for our HT setup for over a year now and wouldn't trade it for anything. I'm looking at getting a 40" LCD to replace our 27" CRT and am going through the trouble of building a sync stripper to allow the xbox to output a VGA signal that should provide better quality than s-video or composite.

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[quote="eeun"]I don't think y

I don't think you'd get sufficient speed on a dual processor lower than 800 MHz.

Yeah, as I said, I'm a little worried about that. I'm not trying to play back HD content, but I am trying to fill an HD display. Do you think that makes a difference, or do you think that just the act of scaling a video up to 1366x768 (720p) or 1920x1080 (1080p) resolution will choke the CPU?

I don't know about Front Row or iTunes, but it looks like QuickTime player is multithreaded for dual CPUs. In my very limited testing on my dual QuickSilver and MDD, when I play a video in QuickTime, Activity Monitor shows a balanced load on both CPUs. Of course, I can't tell if that is an aliasing problem as a result of a slow (1 second) sampling rate masking a bunch of context switching between CPUs or if the video decoding & playback really is balanced on both CPUs simultaneously.

Of course, a dual G4 is better than a single G4 of the same speed because OS X can balance the load between processors: OS tasks can run on one CPU while the video monopolizes the other CPU. But I do also recognize that dual 500 MHz CPUs do not equal a single 1 GHz CPU.

What is XBMC? Is that an app you run on the Mac or the Xbox that allows the Xbox to access content hosted on your Mac? Regardless, I don't have an Xbox. So the cost of an Xbox also blows the budget. Now a PS3 with a Blu-Ray player I could possibly justify. And PS3s can run Yellow Dog Linux, right? Wink

Peace,
Drew

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My two (maybe three) cents

So, a few random observations:

A: I don't have any dual-CPU G4s around to draw any specific conclusions from, but I second the suspicion that video playing is a task that probably wouldn't benefit a lot from the second CPU. OS X does tend to shuffle tasks between cores so often a single-threaded task will appear to be leveraging both in Activity Monitor, but if you look at "top" you can see that said task never gets more then 100% of a *single* CPU. Undoubtedly the second CPU "helps" in offloading other tasks, but I wouldn't buy a dual CPU machine running at a clock rate slower then a single-core machine you *know* is slightly too slow (your G4-667, for instance) expecting the second core to save you.

B: Once and a while I'd hook my 1.33Ghz G4 Powerbook up to the living room set and it seemed to do a passable job scaling "DVD-ish quality" DiVXs and MP4s up to 720p, but I'm pretty sure even it would drop a frame occasionally. So if you're determined to stick with a G4 set your expectations accordingly. ;^) Also note that even the fastest G4s are pretty much useless with HD-resolution files. (Yeah, you said that doesn't matter now, but, who knows, it might later.)

C: Since you said the L-word, I'll note that a relatively ancient 2Ghz Pentium 4/Celeron doorstop with a DVI-port-equipped GeForce 5200 running one of those "settop box" distributions of Ubuntu does a perfect job playing back the sort of videos you're interested in at any resolution up to 1080p. I put together a machine like that with scavenged parts (the only money outlay was $30 for the closeout video card) and it was a *much* more capable video player then the Powerbook. The trick of course is silencing the fan noise to an acceptable level. (But you'll have the same issues with a Mac desktop, and if you end up burning up an old P4, well, you've lost a lot less.)

--Peace

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Re: [quote="eeun"]I don't think y

What is XBMC?

It used to be called Xbox Media Centre, but is now abbreviated to XBMC since it's become multi-platform.
Mine's running on the original xbox, which can be found on the cheap nowadays (I've got three of them now, in case one craps out).
http://xbmc.org/

There's an OS X version, and a a couple variations for the Apple TV if you're so inclined:
http://www.tuaw.com/2008/10/01/install-boxee-or-xbmc-on-an-apple-tv/

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Re: XBMC

What is XBMC?

It used to be called Xbox Media Centre, but is now abbreviated to XBMC since it's become multi-platform...

Just have to say, this looks pretty sexy. I might have to try it on my seriously-collecting-dust TV computer.

(The family getting a Wii for Christmas has sort of rekindled some possible interest in resurrecting it, since a little research revealed that there's quite a bit of support for using Wii remotes as Linux pointing devices. I never bothered with configuring a "front-end" interface on the box since I didn't have a suitable remote-control device, but now... hmmmmm.)

--Peace

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Re: XBMC

What is XBMC?

It used to be called Xbox Media Centre, but is now abbreviated to XBMC since it's become multi-platform...

Just have to say, this looks pretty sexy. I might have to try it on my seriously-collecting-dust TV computer.

(The family getting a Wii for Christmas has sort of rekindled some possible interest in resurrecting it, since a little research revealed that there's quite a bit of support for using Wii remotes as Linux pointing devices. I never bothered with configuring a "front-end" interface on the box since I didn't have a suitable remote-control device, but now... hmmmmm.)

--Peace

To try out your Wiimote on a bluetooth equipped Mac, you can download the demo of Remote Buddy

http://www.iospirit.com/index.php?mode=view&obj_type=infogroup&obj_id=24&sid=8759228Gf9af639d1a84479d&o_infogroup_objcode=infogroup-23&o1_infogroup_objcode=html-115

or

http://sourceforge.net/projects/darwiin-remote/

I have only tried Remote Buddy, but it was pretty cool. I found a battery powered sensor bar that can be used instead of the one attached to the Wii (just a couple of IR LEDs) for cheap. The only thing I couldn't figure out was how to make the Wiimote turn off after not being used. It just wanted to stay on and drain the battery.

Getting back on topic, I had a 1.4 GHz G4 Cube and a 1 GHz Powerbook hooked up to my projecter using Remote Buddy and AirFoil. My thoughts are that anything below 1 GHz just wouldn't cut it, even with a GeForce2 MX or better. I think Eudimorphodon is correct about dual processors not helping playback much, if at all. The real killer for me were the CPU horsepower and USB2 requirements for EyeTV. I'm hoping the new Mac Mini will have the features to make a good media center PC.

Dave...

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I've played around with the W

I've played around with the Wiimote a bit. There was recently an article in Make about it. Remote Buddy is interesting, but like most hobbiest/expiremental software, it doesn't seem ready for prime time yet. As for draining the batteries, you could get one of those rechageable battery/docking station combo job and just craddle the remotes when you are done with them.

What is AirFoil?

I looked up XBMC. That's some pretty awesome eye candy, but it is Intel only. I don't have an x86 Mac to play with. Sad

I have a GeForce 5200 FX and a Radeon 9000 that I can put to use, so video cArds aren't too big a concern for me. But what I'm hearing from folks is that they don't think dual 500 MHz CPUs will cut it. You're probably right! So dual 800s are probably close to the bottom threshold for watchability...

Does anyone else have any experiences they would like to share?

Anyway, I couldn't resist. My sister needs to replace an old B&W (she got an iPod for Xmas so it is time to get her up to USB 2 and Tiger at least), so I picked up a dual 533 Digital Audio for her on the LEM swap list today from a nice guy who cut me a good deal. When it gets here, I'll try it out on my TV before I reconfigure it with some upgrades and send it to her. My experience is that an iBook G4 @ 800 MHz works adequately with my setup, but from what I'm hearing from you folks, I'm not expecting this machine to shine. I'll be sure to let you know how it turns out!

Peace,
Drew

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Results

Well, I got a dual 533MHz G4 w/ a Radeon 9000 and 896 MB of RAM today (still waiting on a 2nd one for my sister after a little confusion on the seller's end). I hooked it up to my TV, set the display to 1280x720 (supported by the TV - not 1080p, but it doesn't waste pixels and it's not stretched).

I can playback an MPEG-4 video alright. According to QuickTime Player, the video I'm playing has the following specs:
Video: MPEG4 720x304 millions of colors
Audio: Stereo AAC at 48kHz
Data rate: 1688.8 kbps

At full screen, there are some occasional dropped frames and obvious lines through the middle of the image where the frames don't line up. It's a little "clipped" or "sheared". I don't quite know the right word to describe the phenomenon, but the playback can't keep up with the refresh rate or something, so there are obvious horizontal lines at the boundary of two different images. It's weird. I also didn't think to write down the actual FPS rate during playback, so I'll repeat that test later and let you know what I get. I'll also scale it up to closer to 720p and 1080p to see how bad that is.

But it's sooo darn close to workable. I wonder if a little overclocking will get me there. Wink

Speaking of overclocking, is there a good guide for Digital Audio daughtercards or can I just use the same ones as for Sawtooth and GigE daughtercards? Also, it looks like Takashi Imai's fantastic "Mystic Room" site (http://www.bekkoame.ne.jp/~t-imai/) for overclocking Macs is offline. First PowerSurge9600's page is down, and now this. That's terrible. Does anyone know for sure if it's gone? I can't read Japanese on the error page I get, but the 404 error is pretty obvious.

Peace,
Drew

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Have you tried Video playback

Have you tried Video playback with VLC? It seems to perform better than Quicktime on most of my machines, except my MBP.

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Okay, I just repeated this te

Okay, I just repeated this test with the video (a rip of Iron Man) playing back full screen in QuickTime Player with the inspector in the foreground. Inspector reported at least 98% of the time that I was at 24FPS. And I didn't see the clipping this time around even though I was watching the same segment. This is at 720p.

Not believing the results, I changed resolution to 1080i (Display Preferences says "1920x1080 (interlaced)" which I presume to be 1080i and not 1080p). I played the movie in full screen again with the movie info window in the foreground, and I'll be damned if it's not playing a 24FPS! Wonderful!

So then I repeated the test with a rip of an episode of the Simon Pegg comedy "Spaced" at 1080i. Specs for the video:
Format: MPEG-4 720x400, millions
Audio: AAC Stereo 48kHz
FPS: 29.97
Data Rate: 1613.66 kbits/s

And it plays back at a full 30FPS!

So there you have it, folks. A dual 533 MHz Digital Audio G4 equipped with 896 MB of SDRAM, a Radeon 9000 AGP 4x card w/ 64 MB of VRAM, and a 100base-T ethernet connection can play back common MPEG-4 video hosted on a server at 720p and 1080i in full screen without dropping frames.

The only problem with this setup is that the fans are rather noisy. I can hear a distinctive "buzz" from the machine. I guess I'll be making a trip to MicroCenter to pick up some quieter fans...

Tomorrow if I get the chance I'll try the test using my single 533 MHz G4

Peace,
Drew

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Re: Results

Speaking of overclocking, is there a good guide for Digital Audio daughtercards or can I just use the same ones as for Sawtooth and GigE daughtercards? Also, it looks like Takashi Imai's fantastic "Mystic Room" site (http://www.bekkoame.ne.jp/~t-imai/) for overclocking Macs is offline. First PowerSurge9600's page is down, and now this. That's terrible. Does anyone know for sure if it's gone? I can't read Japanese on the error page I get, but the 404 error is pretty obvious.

Peace,
Drew

web archive to save the day

www.bekkoame.ne.jp/~t-imai/maine.html

it is a little bit slow but it all seems to be working with pictures, as some sites saved by web archive dont have pictures (or not all of them)

but anyway i own a DA G4 single 533 with 768mb ram with a stock Geforce2 MX and a 120gb HDD. just to test along with you i played the iron man trailer from Apple. the 480P ran about 15-30 FPS, 720P ran from 0-15 FPS, didnt bother with 1080P since 720P was so horrid.

so having a dual 533mhz CPU, more ram, and a better (Radeon 9000) video card does help allot since you can play 720 with a good framerate.

a dual CPU upgrade (like dual 1ghz 7455 or higher) would probably get you what you want to see. but the issue would be finding them. or like you say overclock the CPU a tad. i think you can use a dual 1ghz CPU from a quicksilver in a DA with the 12v mod if i am not mistaken.

since my DA has only a single CPU i would love to see how OS X and videos would run with a dual CPU. even a dual 533 would satisfy me.

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