Advice Regarding ATA100 backwards compatability?

[LotusAstra]

Hi all, i've just bought a new SeaGate ST360020A 60gb HDD and a couple of removable HDD Bays(/Racks)....

The HDD is ATA100 (udma mode5) compatable but i realised when i got home that the removable bays were only ATA66 (udma mode4) opps.... can't take 'em back till next sunday b'cuz they were bought from a computer fair!

Questions are...

• 1. Will they work together anyway and just restrict the new ATA100 Drive to ATA66 with no further probs?
  
• 2. (My MOBO only supports ATA66 mode4 anyway (i think 'cuz my other Mode5 drive is set at mode4))... so even if i do get the ATA100 Removable Drive Bays am i right to say it wouldn't make any difference anyway?

I think the answer to both is yes, however i shall wait for your response! most appreciated for the help, i dont want to try it until i'm sure!

Thx & Regards

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Just my opinions from past experience...and guessing. Post back to let others know if our ideas worked!
BACKUP NOW! u can RESTORE your WHOLE HARD DRIVE and be back in minutes after any BIG Mistake!!!

[bistro]

1. Yes
1. Yes
Yes you are right.

[LotusAstra]

Thx bistro, just wanted to be sure, cool i'll start fitting 'em now...

and hopefully rearange the IDE channels aswell (if they reach), so i can get faster HDD to HDD transfers etc...

glad they'll work cuz it wouldn't have been to cost effective to take 'em back for a swap

Many Thx & Regards

[Philgo]

Lotus, what fair was you at, I went to one at Maidstone.

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Backup Boogaloo, you know it makes sense to do.

[LotusAstra]

I've basically put the drive on same channel as b4 just with the removable bay fitted... until i know whats good and whats not...

1 more thing i just thought of regarding the IDE swapping... i want to setup IDE's as follows in order top to bottom of case...(only top 3 bays can take CD-ROM)

Secondary Master CDRW
Secondary Slave Removable HDD
Primary Slave DVD
Primary Master Fixed HDD

1. Because my secondary HDD is removable i asume it needs to be set as slave so my CDRW (set as master) will work with HDD removed, is that the way it is?

meaning a HDD/CDROM can be set to either MASTER or SINGLE for single drive use?

2. i guess the prefered way is to have the HDD set as master as opposed to the CDROM... or does it not matter, i know both ways will work but, but i mean will there be any performance loss on the HDD b'cuz its running SLAVE to a CDROM?

maybe it depends on what mode the CDROM supports? or not?

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Hi Philgo, i was at the Bristol one (in the train station), quite close to home... Maidstone's a bit far 4 me

Geeez i hate these small HP cases, the back of the removable bay i fitted is about 3mm from the CPU heatsink, and the IDE cables touch the GFX card... hhhmmmm... guess it'll be OK... then-again might be time to buy a new case!

Thanx again

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HP Pavilion 8730uk: Athlon850, 512mbRAM, TNT2 Pro, SB Live1024, DualBoot-Win98FE/XPPro & Cable Modem
Quantum lct15-30 30gb & Western Digital WD450AA 45gb, LG CED-8083b CD-RW, Samsung SD-612 DVD-ROM

[LotusAstra]

right ok... i've read loads of old threads about IDE arangment etc on here and also some other stuff on the net... basically it seems theres many different opinions on it and at the end of the day theres no perfecf configuration...

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In all the stuff i read the only reasons for having it set the way i wanted was for .1. CD to CD copying and .2. better swap file performance on separate IDE

1. i don't have a prob with cd to cd copying (i only have 4x burner)... and 2. my swap file spends 99.1% of the time at zero mb's anyway with tweaks in Win98 and 512mb RAM.
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also I can find NOTHING that says it will improve HDD to HDD transfers (i thought it might have made ghost go faster:confused ... so i from what i read i don't think it will be much benefit to me and i'll leave IDE channels config'ed as they are ie. IDE0 = both HDD's and IDE1 = CDRW+DVD.

I see conflicting things 1 person says putting a CDROM on same channel HDD will slow HDD, then another says it wont make any noticable difference

any other links u could throw my way... in my case do u think its worth swapping them around?

Whats your views on this? i am only going on what i've read recently (and stuff i forgot from before ) just thinking aloud to get your opinions...

Regards

[mpc]

You can add an ATA 100 controller card and they'll run at 100.

Check 'em out here: http://www.promise.com/

[NoBoB]

Drive to drive transfer from channel to channel is dramatically faster than across the same channel. An IDE channel can only do one thing at a time, that is, it can read from one drive or write to another drive, but not both at the same time.

Ghosting from channel to channel is faster. Any data transfer is. That's why it's recommended for on-the-fly CD copying.

You can read these test results from an old test comparing ATA33 and ATA66 drives for data concerning a CDROM and hard drive on the same channel. Note that the results for the HDD alone are the same as for with the PIO Mode 4 CDROM attached, much to the surprise of the test conductors. Their summation is still applicable to today's ATA66/ATA100 comparisons. Since there are no drives currently available that can sustain speeds beyond what the ATA66 standard delivers, there's virtually no advantage to ATA100.

[LotusAstra]

Thx NoBoB, thats just the motivation i need to give it a try, the exellent link shows very little slowdown from having a ROM on same channel as HDD, so i have nothing to loose it seems...

interestingly i read somewhere else that 95% of cdroms might work as a single drive when set as slave, i'm going to test the theory now... EDIT: i just found this to not be true with my drive!... ahh well, HDD will have to be slave to CDROM...

Thx all, still learning, Regards

[This message has been edited by LotusAstra (edited 11-26-2001).]

[LotusAstra]

hi, i've done some tests of my own with sisoft sandra2001 and moving audio files with various IDE configs and found that having a CDROM on same IDE as HDD only has a slight decrease in performance, but, i have found something that goes completly against the general rule about separating IDE devices for faster transfer... heres my results...

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HDD Benchmark with CDROMs sharing same IDE

IDE0 MasterHDD with DVD... 14462... 60gb seagate
IDE1 SlaveHDD with CDRW... 17083... 45gb western digital
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HDD Benchmark with both HDD's on same channel

Seagate Master.......... 19044
western digital Slave... 17121
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HDD to HDD transfer of 688mb .wav album 22-Tracks...

Sharing same channel - Slave to Master.... 1:09
Sharing same channel - Master to Slave.... 1:04
on separate channels - Slave to Master.... 1:19
on separate channels - Master to Slave.... 1:14
on separate channels - Master to Master... 1:14 (Both CDROMS Disconnected too)
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Just for comparison i timed a Partition to partition HDD transfer from within the same drive (45gb WD).... 2:07 (understandably slower)
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so as u can see the HDD to HDD transfers are quite noticably faster when both HDD are sharing the same channel on my system... Huh... tests were done in Win98 with DMA on all drives...

so now i'm quite confused by these results, just a thought but could HDD to HDD transfer be faster when they are on same channel b'cuz DMA is allowing data to possibly bypass the MOBO etc and go direct through the cable HDD to HDD... or don't it work like that, its the only explenation i can think of.... might i see opposite results if DMA was turned off maybe or if i was in DOS?

Advice needed, do these results make sence to u? also in what situation should i definatly see faster HDD to HDD transfers (i would have thought with everything really)?

sorry 'bout all the questions, but after all... i know u guys give good advice!

Regards

[Philgo]

Lotus, I never put a cdrom on the same channel as a HDD, because it was always thought that it slowed the HDD.
I have also read that this is not the case, but I'm still not convinced.
As a matter of interest did you try putting CD's in your drives while testing, to see if that made a difference.

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Backup Boogaloo, you know it makes sense to do.

[LotusAstra]

Thx Philgo, i'm gunna put the 2 HDD's back on the same channel soon, as i've just noticed that when they are sharing with CDROM they are in mode2 rather than mode4... so i think that explains the odd results i got above... doesn't make it a lot slower but as i can find no real gain i think it was better-off setup the way it was b4...

there was no CD in the drives during my testing, i didn't try it b'cuz it wouldn't be a "real-world" test for it as my cdroms are usually empty... i personally can't see it making any difference anyway (all-tho i could be wrong).

i've come to the conclusion that MODE2 CDROM's and MODE4/5 HDD's should only share channels on a older PC in which the MOBO only supports MODE2 anyway (like my other old celeron300a) then i can see that there could be some performance to gain... unless ofcourse they make mode4/5 CDROMS which i don't have for my MODE4 MOBO......

thanx all for the help, Regards


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Just my opinions from past experience...and guessing. Post back to let others know if our ideas worked!
BACKUP NOW! u can RESTORE your WHOLE HARD DRIVE and be back in minutes after any BIG Mistake!!!