More then 4 IDE-Devices -- What? How?
 

This is about upgrading and how to do it so the investment(s) last.

My box is a 700 Mhz Athlon of the year 2000 with 640 MB RAM and still doing fine. Disk Space is becoming crowded though. Current setup:

hda = 10 GB Maxtor
hdb = 10 GB Maxtor
hdc = Toshiba CD-ROM
hdd = LG CD-RW

So the IDE Masters and Slaves are used up (though finegan writes here "Also remember that the onboard IDE controller is another PCI device" (that was new to me).

I know that I can buy an extra IDE-Controller, presumably to be put in a PCI-slot. What about the 33 Mhz limit of the PCI-bus, will that slow a hard disk? Up to what theoretical transfer rate is it becoming a bottle neck or is it?

How will the BIOS get to know the new device(s)? Or does it have to?

Should I switch one or both CD-devices to the new (slower ?) PCI-controller and use them with DMA33 (is that topic connected at all?) and put the new hard disk(s) in their place(s)? As an aside, I anyhow wanted to switch both CD-devices to the slave positions...

Should I consider serial ATA (SATA) hard disk(s) and controller because of better re-useability in the future? Again, what about the 33 Mhz limit of the PCI-bus then?

How would you do it? What would you do?

The speed limit of a PCI bus effects all hard disk controllers equally as far as I am aware. A bigger bottleneck is the fact that the bandwidth of one channel is split between two devices.

The advantage of SATA is speed; ATA are just as reusable IMHO; the PCI bus isn't going anywhere in a hurry.

I would put the new hard disks onto the new controllers first off, then use hdparm to measure how well they perform. If there's no significant performance drop, then leave the CDs where they are; it's better to have a CD and an ATA disk on the same channel because the CD will be used less, giving you a better bandwidth. I would, however, swap hdb and hdd for this reason.

Performance tip: Create a swap partition on each IDE channel; Linux will then use all of these partitions in a RAID-0 type array, making your virtual memory much faster.

Miscellaneous, "just my 2 cents" type of comments:

* If you need to acquire an additional IDE slot, one obvious step you could take would be to simply remove the Toshiba CD-ROM. You would not lose any functionality since the LG CD-RW covers it, and perhaps you might not need an additional controller.

* The practical significance of any potential bottlenecks would depend on how the machine is being used. Are you frequently transferring huge files ("frequently" being defined as several times every time you use the PC) or is the machine usually used for standard Email, web surfing, and the occasional CD burn session? If it's the latter then an occasional bottleneck may not even happen, or may not be worth worrying about on the rare cases that you might see one.

* If maximum performance is a real concern, then you may want to pull the trigger and go all out by replacing the CPU and increasing the RAM. I also try to keep my PC's running as long as possible but there does come a point where you can actually penalize yourself (so to speak) by continuing to use equipment that has become antiquated when compared to modern alternatives. Don't get me wrong, the older equipment may still be perfectly usable, but upgrading to a machine that is literally 3 or 4 times faster than the existing one is a pretty powerful argument.

Sorry for rambling, good luck with whatever decision you make -- J.W.

rjlee's advice on the certain combinations of drives is great -- don't put a hd and a cdrom on the same channel. The PCI bus sports 133MB/s transfer rate, and this is split up over each PCI slot. (If you are using 1 slot, then that slot gets the full 133MB/s) This is why SATA RAID controllers on PCI are stupid. SATA RAID on modern boards that have PCI 1X is great, since that can support 300MB/s.

Anyhow, simple ATA133 (which means the link can do 133MB/s, but the drive can't) drives, especially old ones, aren't generally going to go over like 50MB's. You should pretty much be ok whatever you do. Of course, put your OS and programs drive on one of the channels, not the controller. If you are doing big HD to HD transfers of data, just be aware that if you do two transfers off each one of the controlled drives onto eiether or both of the channel drives, it's probably going to go just fine unless you have a ton of PCI cards like Ethernet, WiFi, TV tuner, Radio Tuner, or whatever. If you have all that and are using them, it will be slower than sucking molasses through a straw north of the arctic circle.

Yesss ... but I don't have many :) As I understand it, this would argue for putting the CD-devices on the PCI-controlled channels since they should need an approximate maximal transferrate of 10 MB/s at 50x speed (if I didn't botch the estimate ;)).

I'm having second thoughts on SATA, I think my mainboard is too old to handle it in the primary IDE channels.

I'm aware of that, that's why I wrote --> "As an aside, I anyhow wanted to switch both CD-devices to the slave positions...". When I plugged the CD-RW in it was the first time I wrestled with internal hardware on my box :D.

Thanks, will do.

Thanks also for your whole post :).

You are right -- in principle ;). Only 1. the Toshiba is faster and 2. sometimes more reliable when reading sub-optimal media (scratched CDs, badly burned CD-RWs, ...) -- and I might need a DVD-reader too, so I'd need a controller anyhow...

Hm yes, it is, you have got me there, but I like my machine in an optimal configuration ;).

That's too early for the things I run on the machine. But no rambling at all, your thoughts have been helpful, thank you :).

Thank you for your input as well (and the information about the transfer rate of the PCI-bus :)). Nice comparison there :D.