How much better a dual G4's than singles?

[drj434343]

I'm looking to get a new tower, for basic webserver stuff. I also need to accomplish some multimedia tasks (like watch TV, play DIVX etc), so my G3 tower isn't fast enough anymore. My question is, how important is it for me to seek a dual G4? They are much harder to find and tend to be a lot more expensive. I was looking in the 450 Mhz -533 Mhz range (Sawtooth G4 (Gigabit ethernet) through Tangent (digital audio)). Is it worth going for a dual? How much better are they? Thanks!

 

[Lord Blackadder]

My G4 (see sig) started out life as a dual 533MHz. The dual CPUs made the machine nearly as fast as a 1GHz G4 in some dual CPU-aware tasks. They make a significant difference in performance over the singles but bear in mind that with CPU upgrades getting cheaper I wouldn't go far out of my way or pay crazy prices just to get a dual. A Sawtooth with a $200 1Ghz CPU upgrade is nice and fast.

 

[SC68Cal]

But a dual 1.8 upgrade would be insane. I know that with the performance that I'm getting off my machine right now, nothing lower than at least a single 1.6 will improve my performance enough to justify it, so why not spend a little extra and get a dual 1.6 and really start burning through apps.

 

[Lord Blackadder]

When I switched from a dual 533 to a single 1.4GHz (a 7455 chip with the big L3 cache), I saw a large improvement all across the board - especially in non-multiprocessor-aware apps. The duals are nice, but they cost an arm and a leg. A single 1.4GHz 7455/57 or a single 1.7/1.8 7447 will make a huge difference in performance, as in good framerates in Call of Duty (if your video card is decent) and massively decreased encoding times in iDVD or Toast.

 

[SC68Cal]

When I switched from a dual 533 to a single 1.4GHz (a 7455 chip with the big L3 cache), I saw a large improvement all across the board - especially in non-multiprocessor-aware apps. The duals are nice, but they cost an arm and a leg. A single 1.4GHz 7455/57 or a single 1.7/1.8 7447 will make a huge difference in performance, as in good framerates in Call of Duty (if your video card is decent) and massively decreased encoding times in iDVD or Toast.

This is true. I don't argue against that point. But I'd probably still be inclined to splurge a little on a dual processor, squeeze a bit more life out of the machine.

 

[drj434343]

point taken, but

When I switched from a dual 533 to a single 1.4GHz (a 7455 chip with the big L3 cache), I saw a large improvement all across the board - especially in non-multiprocessor-aware apps. The duals are nice, but they cost an arm and a leg. A single 1.4GHz 7455/57 or a single 1.7/1.8 7447 will make a huge difference in performance, as in good framerates in Call of Duty (if your video card is decent) and massively decreased encoding times in iDVD or Toast.

You make a good point, and I believe it. However, based on my financial willingness regarding this purchase, I probably won't be buying an upgrade CPU (dual or single) anytime soon, hence my question regarding stock models. Gaming won't be on the agenda, but webserver/filesharing combined with TV tuner/DIVX watching functions will be. In that usage pattern I'm looking at either a dual 450/500 or a single 533, 667, or 733 machine. Given that situation, how would your recommendation change?

 

[Lord Blackadder]

Well, certainly if you can afford a dual go ahead - they do boost performance when an app can take advantage of them.

If you're not gaming, then the only thing that you'll really want more power for is decoding/encoding video (watching a movie or making a DVD).

The single 733 is slower than the dual 533 in most tasks.The dual 533 was faster than any contemporary G4 - the next fastest was the single 933. So if you can get one of those over a dual 500 or single 733 do so.

My dual 533 was a bit slow with iDVD. It worked OK, but if you plan on doing a lot of DVD authoring it would probably be annoyingly slow. For filesharing the 533 will probably be fine. Webserving depends heavily on what your serving and traffic but for a simple site it should be more than adaquate. The TV tuner is another matter, if you plan on recording programs. If you have an EyeTV with a built-in hardware encoder you'll only need CPU power when/if you are authoring DVDs (as mentioned before) or converting formats. If you are going to be doing a lot of that I strongly recommend getting the best CPU upgrade you can afford. If you get one of the cheaper TV tuners (like the EyeTV EZ) that rely on the CPU to do the encoding, anything but a faster (~1.25GHZ+) G4 will be unworkable.

 

[poolin1243]

or you could take a look at my dual 1.44 for sale in the marketplace


but seriously though....

duals are a big difference when it comes to alot of tasks in video and photo editing.

My dual core 2.0 imac with 1gb of ram is only a few seconds faster than the dual 1.4 in that photoshop test up on here...its quite amazing how good these machines are

 

[drj434343]

watch TV, no recording

Well, certainly if you can afford a dual go ahead - they do boost performance when an app can take advantage of them.

If you're not gaming, then the only thing that you'll really want more power for is decoding/encoding video (watching a movie or making a DVD).

The single 733 is slower than the dual 533 in most tasks.The dual 533 was faster than any contemporary G4 - the next fastest was the single 933. So if you can get one of those over a dual 500 or single 733 do so.

My dual 533 was a bit slow with iDVD. It worked OK, but if you plan on doing a lot of DVD authoring it would probably be annoyingly slow. For filesharing the 533 will probably be fine. Webserving depends heavily on what your serving and traffic but for a simple site it should be more than adaquate. The TV tuner is another matter, if you plan on recording programs. If you have an EyeTV with a built-in hardware encoder you'll only need CPU power when/if you are authoring DVDs (as mentioned before) or converting formats. If you are going to be doing a lot of that I strongly recommend getting the best CPU upgrade you can afford. If you get one of the cheaper TV tuners (like the EyeTV EZ) that rely on the CPU to do the encoding, anything but a faster (~1.25GHZ+) G4 will be unworkable.

Unfortunetly, I'm going to be using a cheap analog TV tuner, so I'll assume it is going to tax the cpu. You made it sound like doing any recording will require at least a 1.4 Ghz G4, so I may have to abandon that. I'll assume that simply watching will not be so bad. I'm a bit confused, because some TV tuner manufacturers (like Alchemy TV) state only a G4 400 is required. I guess thats completely inacurate?

 

[jaywong87]

i always wondered, does "dual" mean I get 2x the speed? Like...dual 1.67 Ghz means 1.67x2?

 

[Lord Blackadder]

Unfortunetly, I'm going to be using a cheap analog TV tuner, so I'll assume it is going to tax the cpu. You made it sound like doing any recording will require at least a 1.4 Ghz G4, so I may have to abandon that. I'll assume that simply watching will not be so bad. I'm a bit confused, because some TV tuner manufacturers (like Alchemy TV) state only a G4 400 is required. I guess thats completely inacurate?

When you record video onto a computer, the video is converted into a digital signal and encoded on the fly into (usually) an mpeg file...there are various quality settings. The more expensive boxes handle this by themselves, and the cheaper ones use the computer's CPU for encoding. Any G4 could probably record video from a tuner, but the older machines might not be able to handle an acceptable level of quality for you - and I can't predict just what, say, a dual 500 could handle. I've seen it done on a G5, but not a G4. You can set the quality so high that even a Quad G5 would be stressed, or turn it down for the slowest G4. But I'm not sure what you'll end up with. It might be fine for you, or not.

Just watching TV should be fine. Also remember that recording video uses tons of hard drive space.

Give it a shot and see how it works - it may do what you need just fine.

i always wondered, does "dual" mean I get 2x the speed? Like...dual 1.67 Ghz means 1.67x2?

My dual 533MHz CPUs achieved about a 1.8x maximum speed boost over a single CPU in ideal situations in synthetic benchmarks. that's about the best you can hope for.

 

[drj434343]

other value of duals besides raw speed increase

I've never been one to prescribe that dual CPU's gives twice the performance on normal tasks. I also hear a lot of people talk about dual's being taken advantage of only with software that that is specifically designed for them. But isn't OS X designed for them? Meaning, what I really want out of this system is the ability to host files and serve a website, while at the same time watch TV or listen to iTunes. In that case, isn't OS X smart enough to divy out the tasks being done to both CPU's, effectively spreading the work load? In other words, won't I drastically increase my ability to use multiple apps at the same time?

 

[trogdor!]

its all about what you do with the machine to justify the cost of duals.

 

[drj434343]

its all about what you do with the machine to justify the cost of duals.

That's exactly what I'm asking here. Is what I described above about what I want to use the computer for justify dual processors?

 

[Lord Blackadder]

Yes. OS X and most of the iLife apps are multiprocessor aware (not sure about webserving software).

My point was that, for what you are intending to do, the stock CPUs will be a little slow, and new dual CPU upgrades would be very expensive. A fast new single CPU can be had for relatively cheap and will make a big difference.

Put it this way - a stock dual 533 will run slow if you are recording TV. If you add webserving into the mix, it won't be slowed down as badly as a single 533 would, but things won't necessarily run any faster either. TV recording will still be slow, but the second processor will handle the webserving as well as some of the encoding.

A newer single 1.8GHz CPU in the same G4 box will record TV at higher quality and still have the ability to serve webpages. Everything will run faster. A dual 1.8GHz will run things just as fast as a single 1.8Ghz but again could handle more apps at the same time.

So the dual CPU helps with multitasking, but you won't see a huge

 

[drj434343]

dual 533 tested performance

So I went ahead and purchased a dual 533. Put in 1.25 GB RAM, running stock GeForce 2 MX, 2x250 GB drives. With my Alchemy DVR card (version 2.41), I can record TV at 320x240 30 FPS H.264 codec using about 75% of each processor. I can also record at 640x480 30 FPS MPEG4 codec using only 15% of each processor. That performace is MUCH better than I expected based on what I had been reading.

Anyway, thanks for the advice. Glad I went with the dual.

 

[Lord Blackadder]

Good luck with it - I know that I was pretty happy with my dual 533s, and there is plenty of breathing room for upgrades.

 

[disconap]

My G4 (see sig) started out life as a dual 533MHz. The dual CPUs made the machine nearly as fast as a 1GHz G4 in some dual CPU-aware tasks. They make a significant difference in performance over the singles but bear in mind that with CPU upgrades getting cheaper I wouldn't go far out of my way or pay crazy prices just to get a dual. A Sawtooth with a $200 1Ghz CPU upgrade is nice and fast.

Agreed. I have a Swatooth with a 1gHz upgrade. As Blackadder said, the level 3 cache makes a pretty big difference as well.

If I was going to spend the money on a dual upgrade, I would throw in the extra $50 or so to get the top (I believe right now it's a dual 1.8) over a 1.4 or 1.6. Duals are very pricey and, unless you plan on doing intensive video editing, are probably overkill for the needs you listed. Just my two cents.