Upgrading old low level PC, anyone know about ATA 100 and a 66 MHz FSB

[adiemus00]

I have an older 400 MHz Celeron Gateway computer that I bought a few summers ago. I enjoyed it when it was new, but I have since given it to my mother and moved on to much more powerful (and fun) things.

I'm getting a SCSI drive for my newest computer, so I want to give my 40 GB Western Digital Caviar hard drive to my mother, but it's an ATA 100 hard drive. My current computer has an onboard ATA 100 controller, so her computer will need a controller card. I've found an "ULTRA ATA/100 32BIT PCI 2CH CTRL BIOS CABLE, http://shop1.outpost.com/product/01157 " by Promise Technology to do the job.

My question is . . since the CPU, memory and the motherboard all have buss frequency of 66 MHz, will the ATA 100 card function. I'm not clear on this whole controller card thing. I have a controller card in another computer, but it's an ATA 66 and the computer has a 100 MHz FSB, so I see how that works. I don't know how fast the PCI buss goes or anything. Any advice/information would be greatly appreciated.

Just to note, I don't consider myself a novice in the realm of computers, just seems every time I turn around, there's another detail I need to learn.

[hapoo]

The FSB(front side bus, 100/66 mhz) has nothing to do with ATA100 and ATA66. All ATA Hard drives are backward compatable... meaning you can put that 40 gig drive into a computer made 5 years ago and it would work without any additional hardware.

ATA100 means that the drive can transfer up to 100 megabytes per second. The drive will automatically slow to ATA66, ATA33, or slower if you put it in a slower system. Under most conditions you cant tell the difference between ATA33/66 and 100.

[adiemus00]

That's good to hear, but will an ATA 100 controller card do me any good in that 66 MHz buss frequency?

[hapoo]

Originally posted by adiemus00
That's good to hear, but will an ATA 100 controller card do me any good in that 66 MHz buss frequency?

the bus frequency is just how fast the componants inside on the motherboard itself comunicate with the cpu... your pci bus is still runing at 33mhz (standard pci speed). You can add the ATA100 card if you wish with no problems although i dont see how that would help. Personally I would just connect the hard drive to the controller on the motherboard, you gain very little by adding the controller card.

[adiemus00]

I thank you for all the info, and I don't want to seem ungrateful, but I am curious still. If the PCI buss is at 33 MHz and the controller card is added to allow for ATA 100 compatibility and the motherboard's buss speed is 66 MHz, how (since the hard drive only interfaces with the controller card) does it reap any benefits from the PCI buss? I tried once (a while back, inside of a slightly newer computer than my mother's) directly connecting my ATA 66 hard drive to the regular IDE connection on its motherboard, but the ATA 66 controller card connection was noticeably faster. How can that be with only the 33 MHz PCI buss speed. I can't reconcile the ATA 33/66/100 with MHz and if any of those numbers mean anything that should concern me. I do know that there is a considerable difference between ATA 100 and non-ATA 100 with this particular drive (at least in my current computer), because when I did a recovery once, things were slllllloooooowwwwwwwww until I installed that particular driver. Again, I'm appreciative of any info offered.

[hapoo]

Originally posted by adiemus00
I thank you for all the info, and I don't want to seem ungrateful, but I am curious still.


hehe no prob :)


If the PCI buss is at 33 MHz and the controller card is added to allow for ATA 100 compatibility and the motherboard's buss speed is 66 MHz, how (since the hard drive only interfaces with the controller card) does it reap any benefits from the PCI buss? I tried once (a while back, inside of a slightly newer computer than my mother's) directly connecting my ATA 66 hard drive to the regular IDE connection on its motherboard, but the ATA 66 controller card connection was noticeably faster. How can that be with only the 33 MHz PCI buss speed. I can't reconcile the ATA 33/66/100 with MHz and if any of those numbers mean anything that should concern me. I do know that there is a considerable difference between ATA 100 and non-ATA 100 with this particular drive (at least in my current computer), because when I did a recovery once, things were slllllloooooowwwwwwwww until I installed that particular driver. Again, I'm appreciative of any info offered.


The PCI bus is running at 33 million cycles per second. Thats all the mhz means. As far as its speed goes you'd have to check and see how much it transfers every cycle. The PCI bus can transfer hundreds of megabytes per second... much much more than your hard drive can. If your wondering about compatability... no worries, All PCI cards will work on a system with a system bus of 66, 100, and 133 (notice they are multiples of 33, the same mhz as the PCI bus).

Your hard drive is ATA100 meaning it can send upto 100 megabytes per second. The hard drive your talking about can transfer about 25 megabytes per second continuously and can burst upto 100 megabytes per second. If you connect the drive to a ATA33 controller it will still transfer at 25 megs continuously but it will only burst up to 33 megs a second. Depending on your application you wont notice that much of a difference. When looking for a good drive you should be more intrested in the continuous read/write speed rather than the burst speed. Any other questions? :)

[Edited by hapoo on 06-18-2001 at 04:42 PM]

[adiemus00]

No more questions. You've been really helpful. I'm pretty sure things will all work out now. They probably would have without my checking, but I feel better about making this move with some knowledge about it. :) Thanks a lot.