Speed: ATA/66 vs. ATA/133

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Level 1

10 points

Speed: ATA/66 vs. ATA/133

I currently have 4 HDs in my MDD: the original IBM drive that came in the computer is ATA/100, and the other 3 (all Maxtors) are rated as ATA/133. Unfortunately, one of these ATA/133 drives sits in the MDDs ATA/100 bay (along with the IBM), and the other 2 are in the ATA/66 bay. I'm thinking of getting a Sonnet ATA/133 PCI card, and running all of the drives from it. Of course Sonnet says I'll see a huge increase in speed, but they're trying to sell me a card. What is the real speed difference between ATA/66, ATA/100, and ATA/133? Is it worth 100 bucks?

Dual 1.0 GHz MDD Mac OS X (10.4.7) 1.75GB, 4x Superdrive, Radeon 9600

Posted on Sep 11, 2006 5:39 PM

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Answer 1

Sep 12, 2006 1:07 AM in response to rdaveh

Hi

I expect you'd see some speed increase although not huge. As far as I'm aware there's little real difference between ATA/100 and ATA/133, as the internal transfer rate of all ATA drives is less than 100MBps. There may be some real difference between ATA/66 and ATA/100, although it will still be less than the theoretical maximum of 100MBps.

One of the performance hits using ATA drives is due to two drives sharing the same channel and contending for bandwidth. If you did buy a PCI card, it may be better to run two drives off the card (each one it's own channel/ribbon cable) and two drives directly off the logic board (one on the ATA/66 bus and one on the ATA/100 bus). It partly depends on what you use the drives for though and how often you use both drives on the same bus simultaneously (copying from one to the other etc).

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Answer 2

The hatter

Level 9

61,031 points

Sep 12, 2006 5:30 AM in response to rdaveh

There is a small difference of 3-4% or about 2MB/sec between the ATA/66 (ATA-$) and the ATA/100 (ATA-6) bus in your MDD. There is no benefit from PCI controller other than you then can have two of the drives on the Sonnet on their own channel and not sharing a bus (you would not want to put all the drives on it though, zero benefit).

The MDD is pretty good though on sharing an IDE bus.

Serial ATA would be nice, long thin cables. Also, Using FW800, only one drive per card, will get slightly better than the ATA/100 bus, and for only $50.

I would look at external SeriTek card and case for expansion, RAID and to improve performance.

And replace the OEM drive.

All of this to.... get better disk I/O? Get a 10K Raptor boot drive. Good long term investment.

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