View Full Version : iMac G5 speed vs. PowerBook G4
Ok, I'm beginning to panic: I ordered a 20" iMac (1.8Ghz) and increased the RAM to 512Mb as a BTO option. I've as good as sold my iMac G4 1Ghz (I'm just holding on to it to run the G4-G5 data transfer App when the new iMac arrives).
I'm now getting worried that more and more forum posters with hands on experience of the G5 iMac are saying that the speed difference is negligible from say a G4 Tower or even worse, the G4 iMac (that I'm ditching :eek: ).
To top it all off, the sale of my iMac G4 & my iBook G4 are both going to buy me a refurb 15" Powerbook - probably a 1.25Ghz or if the Refurb Gods are smiling on Wednesday, a 1.5Ghz.
Am I going to be gutted to find out that not only is my G5 not much faster than my old iMac, but that my new Powerbook will actually be quicker?!?!
I guess I'm after reassurance I'm doing the right thing!! ....I could always cancel the iMac... (I've got until Oct 5th before delivery).
All thoughts/suggestions/opinions appreciated :o
Based on my experience in a 30 minute hands on session with a G5 iMac I don't think that the PB will be faster than the iMac. I have a 1.33 12" PB and the iMac was definately faster. I think that your G4 iMac will be a little slower than the G5 iMac but you will be able to tell the difference.
bassplayinMacFiend
2004-09-24, 09:31
I just got "the call" from the Apple store (where's Phil Rizzuto when you need him?) and they have a 20" iMac G5 with my name on it. :D Once I've added more RAM I'll compare the performance of the iMac against my PBG4 1.25GHz 15" AlBook that I picked up this month last year.
Looking at online tests it seems the PBG4 will do better in GPU intensive tasks and the iMac G5 wins in CPU intensive tasks.
If there are specific tasks you want me to compare between these computers then post 'em here.
Cool! I'd be really interested in hearing how they compare in real life usage rather than a benchmarking program.
revolver
2004-09-24, 14:16
I have a Powerbook G4 1.5Ghz, 1Gb RAM, and I can attest, using no benchmark scores- just "feel"- from playing around with a G5 doing tasks that I typically do everyday with my PB that:
At a stock 256Mb RAM configuration, the iMac is considerably more sluggish than my G4.
I went in to the Apple store wanting to love it enough to buy it. I walked away completely underwhelmed and perfectly content with my G4.
Other thing worth mentioning not related to speed:
The screen has a more jagged, contrasty appearance. The screen on my powerbook is much smoother. Compare the corners of, say, the Safari browser window. On my PB, it's totally smooth. On the iMac, I can see the jagged pixels.
At a stock 256Mb RAM configuration, the iMac is considerably more sluggish than my G4.
Oh great, just what I didn't want to hear :( Now I'm even more confused...
Thanks for the info though...
Oh great, just what I didn't want to hear Now I'm even more confused... With the stock 256 MB of RAM, OF COURSE it's slower than the PowerBook with 1024 MB of RAM!
Any Mac running OS X is going to quickly start lagging with only 256 MB of RAM. Most folks consider 256 MB to be an absolute bare minimum for casual use and 512 MB a more comfortable amount for day-to-day activities.
With equal amounts of RAM, the iMac G5 should definitely beat the PowerBook with the slower G4, slower drive, and slower bus.
You need a minimum of 512 MB of RAM. That's what Apple should include on their low end systems that currently ship with 256 MB. I would expect the new iMacs to perform quite a bit better than the PowerBooks. They have a 300 MHz higher clock speed, which helps a bit, and perhaps more importantly they have faster hard drives. 7200 RPM vs. 4200 RPM (or 5400 RPM if you BTO it on the PowerBook) will make a significant difference.
If you were to compare, say, a 1.5 GHz G4 desktop system to a 1.8 GHz G5 iMac, and the desktop had the same hard drive, video card, and amount of RAM, I don't think performance would be all that different. The G5 is really not much better than the G4 clock-for-clock, and 300 MHz won't make a huge difference. But if you combine that with a faster hard drive then you're in much better shape.
http://www.macworld.com/2004/09/features/imacbenchmarks/index.php
I am surprised at the scores really.. the 1.5 G4 powerbook still stacks up pretty well judging by those numbers (making edumakated guesstimates). Which is good .. *hugs powerbook*
revolver
2004-09-24, 23:27
Well, one thing I neglected to mention is that my powerbook has 128MB video RAM and the BTO 5400RPM hard drive, so it's about the fastest G4 PB you can get.
I don't doubt the G5 iMac will be faster when tricked out with a gig of RAM. I was just surprised that the stock configuration of this supposed screamin' speed demon was pretty lame compared to my G4 PB.
Apple has done a disservice to their loyal and potential customers by requiring an upgrade right out of the box. I mean really, lets cut the BS about $1299. It's $1500 with passable RAM and a halfway decent sized hard drive.
Just for reference, Macworld numbers from July for the PB... with the G5 iMac numbers beside it. Both systems ran with 512 MB ram, as specified in their benchmark information. The PB is semi-close in most tasks, with the exception of Cinema 4D.
Mods: format seems a little odd with the code tags (it's making the reply size a little wide)... hope it's okay.
PB 15" 1.5 GHz iMac 17" 1.8 GHz G5
Speedmark: 136 162
Cinema 4D: 4:33 3:02
iMovie: 0:56 0:40
iTunes: 2:26 1:52
Photoshop CS: 2:00 1:51
Unreal Tournament: 26.1 fps 33.6
A friend of mine (who doesn't post here) told me that someone else tried doing a little iTunes importing benchmark with an iMac G5. Import speeds were about the same whether processor performance was set to automatic or highest when reading from the optical drive - a rather pitiful 9-11x. My dual 500 way back was about that fast. However, when reading straight from the hard drive it was much faster, around 22x. So slightly faster than my 1.33 GHz G4 tower.
The problem is due to the G5's architecture. It has a 20 stage pipeline, very little L2 cache, and the G5 in the iMac is stuck with a slower bus as well. They don't make a good combination. Not that the iMac will be slow per se, but if I were in the position to be buying something like it, I'd rather spend $1300-$1500 on a 20" G4 iMac than a 17" G5 iMac. Or I'd just wait for the next revision.
I don't feel so bad now - I BTO'd the iMac to 512Mb on one stick because I'll be ordering another 512 from Crucial as soon as I get the dispatch email from Apple. I guess it shouldn't be too bad after all....
revolver
2004-09-25, 15:22
Take a look at this comparison between the iMac G5 and the powerMacs/Powerbooks
http://www.barefeats.com/imacg5.html
I was not crazy. the powerbook 1.5Ghz more than holds its own against the G5 iMac. In fact it beats it in many categories- including UT2004 and HALO framerates- the very tests Apple boasts the iMac beats its predecessor by 200%!
The iMacs in this test were loaded with 512MB. The notation in the test indicates that 2 512 or 1GB DIMMs increases performace by perhaps 30%- but untested. Powerbook specs not noted.
I'm not trying to trash the iMac. I think it's a slick machine, but Apple marketing will have you believe it runs circles around the current technology- which does not seem to be the case.
Take a look at this comparison between the iMac G5 and the powerMacs/Powerbooks
http://www.barefeats.com/imacg5.html
I was not crazy. the powerbook 1.5Ghz more than holds its own against the G5 iMac. In fact it beats it in many categories- including UT2004 and HALO framerates- the very tests Apple boasts the iMac beats its predecessor by 200%!
The iMacs in this test were loaded with 512MB. The notation in the test indicates that 2 512 or 1GB DIMMs increases performace by perhaps 30%- but untested. Powerbook specs not noted.
I'm not trying to trash the iMac. I think it's a slick machine, but Apple marketing will have you believe it runs circles around the current technology- which does not seem to be the case.
:err: Are you trying to mix two comments into one statement? The PB will obviously beat the iMac in a test that stresses the GPU more than the CPU, and where the PB has a much stronger GPU. Granted, the G5 iMac doesn't beat its predecessor (G4 iMac) by 200% in gaming, but it was faster (by 10%).
That set of benchmarks was heavily GPU focused, so it's a given that the PB would do extremely well in comparison. Only Cinebench/Filemaker appear to be more CPU based, and the iMac did well in those benchmarks.
revolver
2004-09-25, 18:49
Well, the point of the original question was whether the poster would end up with a faster powerbook than iMac G5.
Taking all GPU-intensive tasks off the table and focusing on marginally faster CPU-intensive scores is misleading. My contention is that for the iMac in the stock config- or even with 512MB of RAM- a G4 powerbook is at least as fast- and in GPU intensive tasks significantly faster- than this machine.
Maybe throwing in 2 matched 512MB DIMMS throttles the iMac past the powerbook. That's the iMac advantage.
But... Imagine buying a spankin' new $2000 desktop and an Apple store employee saying "The G4 PB will obviously beat the iMac in a test that stresses the GPU more than the CPU, - the G4 PB has a much stronger GPU" just as you are about to fork over the 2 grand?
and
"Well, It's not exactly 200% faster than the G4 iMac in gaming like Apple marketing claims, it's more like 10%. But that's still faster, right?"
Maybe throwing in 2 matched 512MB DIMMS throttles the iMac past the powerbook. That's the iMac advantage.
When you say 2 matched DIMMS do you mean 2x512's, 2x1Gb's - whatever. Or do you mean 2 DIMMS made by the same manufacturer? If the former, what would be wrong with having say one 512 DIMM and one 1Gb DIMM?
bassplayinMacFiend
2004-09-26, 08:56
When you say 2 matched DIMMS do you mean 2x512's, 2x1Gb's - whatever. Or do you mean 2 DIMMS made by the same manufacturer? If the former, what would be wrong with having say one 512 DIMM and one 1Gb DIMM?
Matched RAM means that both sticks of RAM are of the same size, speed and latencies. The basic description of iMac G5 RAM is that it is unbuffered PC3200 184 pin DIMMs.
With unmatched DIMM chips you still use all of the RAM on the chips so in your example of 1GB and 512MB sticks you'd still have 1.5GB RAM addressable and useable to you.
What you don't get is a 128 bit buss. With a 128 bit buss you get 2 64 bit busses, one going to RAM and one coming from RAM so you can send messages to and receive messages from RAM at the same time. With a 64 bit buss you can only do one of these at a time.
bassplayinMacFiend
2004-09-27, 09:35
The only test I've done so far is compiling my Musical Scales program on my new iMac. On my PowerBook, it takes maybe 10 seconds to link and compile (for deployment, not using zerolink). On my iMac, linking & compiling is nearly instantaneous. I was looking for the blue progress bar but my program was already launching!
The iMac is still at 256MB RAM at this time. Hopefully my new RAM will be here by the end of this week.
Are there any tests people want me to run on both machines?
Yeah, I'd like to see what the average import rate is on a cd in iTunes. Somebody mentioned that before but it seemed pretty screwy to me. Luca said it was around 9-11x which doesn't make any sense to me. Way too slow. My 700mhz G4 iMac gets between 5-7x with only 256 meg of RAM.
bassplayinMacFiend
2004-09-27, 10:43
Yeah, I'd like to see what the average import rate is on a cd in iTunes. Somebody mentioned that before but it seemed pretty screwy to me. Luca said it was around 9-11x which doesn't make any sense to me. Way too slow. My 700mhz G4 iMac gets between 5-7x with only 256 meg of RAM.
You gotta remember, CD input speed is bound by the speed of the drive that reads the CD. For example, if you had a CD-RW/DVD-ROM drive, your CD read speed = 32x.
On the new iMac G5's the CD read speed = 24x, so the drive itself is actually slower than the drive in your iMac. If your iMac G4 has a DVD-R drive, then that drive is 24x also and you would be comparing apples to apples, as it were.
Yeah, but 24x is way above 11x. I know someone with a dual 867 who can import CDs at nearly 30x, and the drive in it has a max read speed of 32x.
It's either an issue of the optical drive spinning far slower than it should, or the "brain" of the machine (CPU, bus, memory, cache, etc) not being up to the task. Either way, it's a problem.
bassplayinMacFiend
2004-09-27, 11:03
Well, once I've received and installed RAM into my iMac, I'll gladly post import times. Of course, this begs the question, what format & bit rate should I test at? I mean, I imagine that importing & encoding to a 320kbps mp3 is less CPU intensive then importing & encoding to 128kbps or less. Does anyone know what import settings were used? Without that information you don't know what you're comparing.
True. However, I haven't noticed huge differences between bit rates. I'd say encoding at 192 kbps CBR MP3 would be a pretty good middle-of-the-road test. You can also try 128 kbps AAC since everyone seems to love that so much :p.
Probably the most important thing is that you compare the import speeds from the optical drive to the speed when ripping directly from the hard drive. I'm just looking for a general idea of how fast it is... if it's ripping at 10x then you know there's some kind of a problem, regardless of bit rate.
bassplayinMacFiend
2004-09-27, 12:01
Well, I can't contact newegg.com for whatever reason, so I have no idea how long it'll be until my RAM ships. Oh well, guess it's time to play another waiting game. :)
bassplayinMacFiend
2004-09-27, 16:44
I did a quick rip of Slayer - Reign In Blood to see what kind of encoding times I'd get. First of all, I set import to 320kbps mp3 (MY default) with error checking off.
One thing I noticed is the encoding multiplier increased for the later songs on the CD. This makes sense since these songs are stored on the outside of the CD where more of the CD will travel under the laser per revolution than the tracks recorded closest to the middle of the CD.
That said, the earlier tracks ripped between 7-10x, while the later tracks ripped between 14-16x. I don't know if RAM would play a role in ripping speed but I will try again once I have my matched RAM sticks.
For whatever reason I still cannot connect to newegg.com so I'm kinda worried about my order. Hopefully the warehouse is still working and the site being down (all day!?!) is just some kind of glitch.
Well, those are some rather pitiful import speeds. It's rather depressing actually. My 2.4 ghz dell gets around 15-20x. I was hoping that it would be higher than that. Though, that's not at all a fair comparison, I was just expecting that with a G5, these new iMacs would be wicked fast, considering that the G5 is the only thing it has going for it as far as new features. Could the 256 in RAM have a lot to do with it?
More RAM could help... probably will. I guess if you have more RAM, your computer will be able to move more of the data from the CD to the RAM so it's quicker to import.
Have you tried importing straight from the hard drive? Because those seem like pretty crappy speeds. I mean, I have a 1.33 GHz G4 - 500 MHz slower AND on a processor most people are determined to call "crappy" or "old." Yet my import speeds are 17x-21x.
I do know that G5s are better at some tasks than G4s, and vice versa... one is good with integer things and the other is good at floating point things... I really don't know the difference but perhaps iTunes encoding relies more on whatever the G4 is good at? I'm not sure. I'd be interested to see how it goes if you rip from the hard drive.
bassplayinMacFiend
2004-09-27, 18:02
Well, those are some rather pitiful import speeds. It's rather depressing actually. My 2.4 ghz dell gets around 15-20x. I was hoping that it would be higher than that. Though, that's not at all a fair comparison, I was just expecting that with a G5, these new iMacs would be wicked fast, considering that the G5 is the only thing it has going for it as far as new features. Could the 256 in RAM have a lot to do with it?
I'll try again once I have more RAM. I guess I should try different encoding settings to see if that affects import speed. What are your import preferences on your dell?
bassplayinMacFiend
2004-09-27, 20:31
More RAM could help... probably will. I guess if you have more RAM, your computer will be able to move more of the data from the CD to the RAM so it's quicker to import.
Have you tried importing straight from the hard drive? Because those seem like pretty crappy speeds. I mean, I have a 1.33 GHz G4 - 500 MHz slower AND on a processor most people are determined to call "crappy" or "old." Yet my import speeds are 17x-21x.
I do know that G5s are better at some tasks than G4s, and vice versa... one is good with integer things and the other is good at floating point things... I really don't know the difference but perhaps iTunes encoding relies more on whatever the G4 is good at? I'm not sure. I'd be interested to see how it goes if you rip from the hard drive.
What are your import settings? What are the average song lengths on the CDs that give you 17-21x. Or is that every CD? I've only tried one CD at 320kbps so I definitely wouldn't consider that any kind of definitive benchmarking, that's for sure.
Again, once I get more RAM I'll try some more.
One question, how do I copy the CD to my hard drive? Or are you saying to make a dmg and import from that?
Well, I generally import at 192 kbps or 320 kbps. That's for a pretty standard CD... I think it was Sgt. Pepper that I did.
Anyway, it's easy to copy the CD. Just drag all the tracks from the CD onto your computer. They're AIFF files. You can add them to your library, then select them and choose "Convert To MP3" from the Advanced menu. That does the same as importing from the CD.
bassplayinMacFiend
2004-09-27, 20:50
Well, I created a Sd2f image file using Toast 6, then mounted that and imported at 320kbps mp3. The import occured at 32x.
Well, I created a Sd2f image file using Toast 6, then mounted that and imported at 320kbps mp3. The import occured at 32x.
Maybe I have low standards for audio quality. I use AAC at 128kps. I think that's iTunes' default. With a higher compression like that, though, I would think that it would take longer to import, but maybe I'm wrong about that.
You're importing fast from the hard drive which means that it is encoding quite quick. I don't know why it wouldn't be getting those speeds from the disk drive. It should read cd's at 32x or 24x, I don't know which it is. Very strange to me.
bassplayinMacFiend
2004-09-28, 11:49
Maybe I have low standards for audio quality. I use AAC at 128kps. I think that's iTunes' default. With a higher compression like that, though, I would think that it would take longer to import, but maybe I'm wrong about that.
You're importing fast from the hard drive which means that it is encoding quite quick. I don't know why it wouldn't be getting those speeds from the disk drive. It should read cd's at 32x or 24x, I don't know which it is. Very strange to me.
It's all in what you're into I guess. Being a bass player, I need higher quality audio files. The bass becomes way too muddy and sometimes even too overpowering for my taste at 128kbps.
My iMac's drive is rated as 24x read so I'd think it should be pulling off the CD as fast as possible. I'm just not sure the CD reader is running at full tilt though. Once I get my new RAM in I'm going to do a bunch of tests including:
[EDIT]
I decided not to go crazy, it's not that important to me. I did install FCE 2 today and that CD was revolving considerably faster than my audio CDs. Knowing this, the import speed is limited more by the drive than the CPU etc.
Anyway, now that I have 2GB RAM with the 128 bit buss enabled this thing screams! Maya opens on the first try in 9 seconds. GarageBand opens a 2 track audio file in about 8 seconds. iTunes opens in 3 seconds, XCode opens in between 4 - 6 seconds. Terminal opens in less than 1 bounce.
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