Mac Mini vs. G4 tower

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Hawaii Cruiser's picture
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I picked up an Intel Mac Mini 1.6GHZ duo core, 250GB 5400 SATA1 hard drive, 2GB RAM running OS 10.5.7. My wife has a MDD G4 dual 1.25GHZ, 300GB 7200RPM PATA/100 hard drive, 2GB RAM running 10.4.11 which she does some video work on sometimes. Is the Mini going to smoke the MDD G4 overwhelmingly in iMovie? Primelabs Geekbench puts the MDD at 1051 and the Mini at 2138, but how much do the other factors besides processor and memory close the gap between the two? And what about the heat factor and wear and tear on the machines doing video?

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Dr. Webster's picture
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The mini has the advantage ov

The mini has the advantage over the G4 in everything but random disk I/O and graphics, because of its 5400rpm drive and integrated video. For video editing work, you probably won't notice the difference in graphics since the CPU shoulders the rendering load, but you probably would see that difference in disk speed. Drop in a 7200rpm 2.5" drive and the mini will beat the pants off the G4.

The mini is pretty well-designed thermally; I've put mine under heavy load and experienced no problems. Having its power supply be external certainly helps.

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burning down the house

Did Apple ever give a good reason for downgrading the video on the Intel Minis? Was it simply to keep costs down? Seems pretty creepy and disrespectful of it faithful clientelle to have only offered such a fixed downgrade.

I always look at a 3.5" drive and a 2.5" drive and assume the failure rate on the smaller drive is going to be higher and much sooner. Is that assumption incorrect? Is the construction not more flimsy on the smaller drives? Do the 2.5" drives overheat higher and faster? It just seems like you'd burn out a Mini long before you'd burn out any kind of tower. I guess that's not really a big question for people doing heavy duty video work. They're going to afford a Mac Pro all the same.

I'm reading elsewhere that the seek times on the smaller platters, though, can be faster, which sounds like they'd be better for video.

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I'm sure the reason for integ

I'm sure the reason for integrated video is cost, and, more importantly, size limitations on the motherboard. Have you ever seen a mini's logic board? Not only is it tiny, but it's PACKED. I don't know where they'd stuff a discrete graphics chip (and its necessary heatsink).

Believe it or not, but 2.5" drives used in desktop environments generally have a better life expectancy than 3.5" drives. Their platters are smaller (less rotational mass for the motor to spin) and their actuator arms are smaller (meaning they have less distance to travel). In fact, servers are moving more and more towards 2.5" drives, and Seagate's 15k 2.5" SAS drives have the fastest access of any hard drive, period, with excellent MTBF. Granted, you can't install a 2.5" SAS drive in a mini, so for hardcore video editing you're still best off with a Mac Pro.

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Re: burning down the house

Hawaii Cruiser wrote:

Did Apple ever give a good reason for downgrading the video on the Intel Minis? Was it simply to keep costs down? Seems pretty creepy and disrespectful of it faithful clientelle to have only offered such a fixed downgrade.

I'm sure that Apple would of offered "integrated video" on their G4 models if there had been a readily available chipset to let them do it. They used a discrete Radeon (the cheapest they could get, with built-in memory) in the Mini so they could use the same system controller IC across their whole line. (And thus only had to design it once.)

--Peace

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I had a 1.83ghz mini and it r

I had a 1.83ghz mini and it really smoked my G4. To speed things up even more I made an external firewire drive my boot drive.

Wayne

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How does using an external fi

How does using an external firewire drive as the boot drive speed up the system? Was rpm the factor there?

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Re: How does using an external fi

Hawaii Cruiser wrote:

How does using an external firewire drive as the boot drive speed up the system? Was rpm the factor there?

The external firewire drive accesses and moved data faster. When I put my system on the external drive, my mini booted faster and opened files noticeably faster. The internal drive was a 5400 rpm 80gb while the external contained a 320gb 7200 rpm drive

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How does that work?

I've always been curious as to how the numbers work on this internal drive vs. external firewire drive issue. The onboard SATA bus is much faster than the firewire connection, is it not? Is the rpm factor significant enough to overcompensate for the onboard speed? How do the megabytes and the megabits work on this? If both the internal and external hard drives are 7200rpm, will not the internal smoke the external with comparable drives? Then dropping the internal drive to 5400rpm, the seek time slow down is significant enough that the firewire connection suddenly surpasses the internal bus? 7200 to 5400 is a one quarter drop in rotation speed, so that is pretty significant, and that's a mechanical devaluation as opposed to a...what would you call it, potential bandwidth devaluation? And even though SATA is much faster than firewire, the SATA bus will never come close to saturation while the firewire will get closer, so the potential speed gap may be large, but the reality gap is not as large... Am I on the right track here?

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There are three things to thi

There are three things to think about when it comes to hard drive performance:

1. Random I/O
2. Sustained (sequential) I/O
3. Cache

The first two are somewhat related by the spindle speed of the drive, as well as the drive interface. SATA is significantly faster than PATA on paper, and moderately faster in practice.

Again, since the mini comes with a 5400rpm drive (probably with an 8MB cache), it's at a disadvantage despite the better bandwidth that the SATA bus provides. The external FireWire drive may be limited to a 400Mbps (note that's megabit, not megabyte) bus, but it's likely to be a 7200rpm drive with a 16MB cache, which helps it with both random and sustained I/O.

That said, booting and running an operating system is more on the "random I/O" end of the spectrum, thus the FireWire drive will win...it doesn't have to shovel a ton of data across the bus, it just needs to find it quickly. I suspect, though, that a large file copy to both drives will show that the internal 5400rpm drive will be faster, simply because that's a sustained write (which are the easiest kind of operation for drives), cache doesn't matter much, and you have much better headroom with SATA.

I might as well note here that I've heard of plenty of Mac mini users booting from FireWire drives...but all of them had G4 minis, with 5400rpm PATA internal drives. The 5400rpm SATA drives that come with the Intel minis these days are much better performers. (And, again, 7200rpm 2.5" drives are cheap these days, and are pretty easily swapped into an Intel mini using Tom's takeapart guide.

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Fascinating. Thanks to the go

Fascinating. Thanks to the good doctor.

So taking that one step further, if both drives, SATA and firewire, are the same rpm and cache, in random I/O, as in booting and running the system, they will perform almost equally, except, as stated earlier, the 2.5" may have better seek times because of its smaller mechanisms? With random I/O and sustained together, the SATA will beat the firewire significantly. Seeing as I've spent a great deal of my life fixing the wife's computer probably because of the heavy fragmentation and corruptions caused by working with video files, and the better setup would be to have the system and the video files on separate partitions or drives, the best setup with a Mini for such work would be to have the system on the firewire drive and the video files stored on an internal SATA 7200rpm drive in the Mini since working with the video files would be sustained I/O so they'd be best kept by themselves on the SATA bus. I could have two partitions on the internal drive instead, but the safest way would be with the firewire drive setup. That would also leave me plenty of room for the large video files on a single partitioned internal drive.

By Jove, I think I've got it.