Are firewire hard drives faster than SCSI hard drives?

[ahsia]

If so, why aren't more people using firewire?

 

[Zlash]

No, but firewire is great for external stuff. Hard drives, digital cameras, scanners etc.

 

[evilOlive]

Medium Mbps (Mega BITS per second)

SCSI -------------------------------------------- 40,000
SCSI-II (Fast) 8Bit/Narrow ----------------- 80,000
SCSI-II (Fast) 16Bit/Wide ------------------ 160,000
SCSI-III Ultra Narrow ----------------------- 160,000
SCSI-III Ultra Wide -------------------------- 320,000
SCSI-III Ultra2 Narrow ---------------------- 320,000
SCSI-III Ultra2 Wide ------------------------- 640,000
SCSI-III Ultra3 Narrow ---------------------- 640,000
SCSI-III Ultra3 Wide -------------------------1280,000

vs.

FireWire --------------------------------------- 400,000
FireWire II (Prototyped) -------------------- 800,000

 

[Pariah]

There'a actually no such thing as a firewire hard drive. They're all IDE drives in firewire enclosures. If a make believe zero penalty IDE to firewire bridge is used, the comparison comes down to IDE vs SCSI in speed.

EvilOlive, you need to take off the last 3 zero's in all those numbers. Firewire is 400Mbits/s (50MB/s), not 400,000 and so forth. People understand MB/s better as well:

SCSI -------------------------------------------- 5
SCSI-II (Fast) 8Bit/Narrow ----------------- 10
SCSI-II (Fast) 16Bit/Wide ------------------ 20
SCSI-III Ultra Narrow ----------------------- 20
SCSI-III Ultra Wide -------------------------- 40
SCSI-III Ultra2 Narrow ---------------------- 40
SCSI-III Ultra2 Wide ------------------------- 80
SCSI-III Ultra3 Narrow ---------------------- 80
SCSI-III Ultra3 Wide -------------------------160

vs.

FireWire --------------------------------------- 50
FireWire II (Prototyped) -------------------- 100

 

[Mavrick007]

<< There'a actually no such thing as a firewire hard drive. They're all IDE drives in firewire enclosures. If a make believe zero penalty IDE to firewire bridge is used, the comparison comes down to IDE vs SCSI in speed. >>


I disagree a bit to this just cause it comes down to the bus. IDE and Firewire aren't the same bus transferring info back and forth. The drive might physically be like an ide drive, but it doesn't pass the data the same way as normal IDE does, nor does it have the limit of the IDE channels. I'm not sure if it's based off of the PCI bus or not, but SCSI cards have to operate off of PCI so it's hard to compare that too. This is just like how you have USB hard drives now too. It's a different bus offering different speeds as well as strengths and weaknesses.

 

[Gunbuster]

<<The drive might physically be like an ide drive, but it doesn't pass the data the same way as normal IDE does>>


It IS an IDE drive, the firewire interface plugs into the IDE connector inside the enclosure, hence the firewire chipset must talk to the HDD the same as a normal IDE chipset

 

[KenAF]

There are one or two native Firewire drives, but these are slow/obsolete 5400rpm models.

All other Firewire drives are simply regular ATA drives on an ATA66 interface (controller) to Firewire adapter. So first you are dropping an ATA100 or ATA133 drive to ATA66 speed, and from ATA66 speed you are dropping it to Firewire's 50 megabytes/s max throughput.

SCSI Ultra160----------------------------------160
SCSI Ultra320----------------------------------320

FireWire (current)------------------------------ 50
FireWire II (Prototyped) -------------------- 100

ATA66---------------------------------------------66
ATA100------------------------------------------100
ATA133------------------------------------------133

 

[Mavrick007]

<< <<The drive might physically be like an ide drive, but it doesn't pass the data the same way as normal IDE does>>


It IS an IDE drive, the firewire interface plugs into the IDE connector inside the enclosure, hence the firewire chipset must talk to the HDD the same as a normal IDE chipset >>



Ok, since Firewire is connected usually by a card off of the ide bus, then it has to transfer data at ide rates, but this can nowhere meet the max potential to firewire. We're only really going to see about 15MB/s going by cable to the card through the ide bus. This is not getting anywhere near 400 Mbits/s, so until there's some spec changes to how Firewire is implemented (like directly on the mobo with it's own separate bus), then it will still operate like ide and will not even touch SCSI speeds. Right now it's just good cause it's hot swappable and a large rewritable storage device(in terms of hard drives). Scsi is still the champ for speed. Theoretically, Firewire has the potential of exceeding the fastest Scsi.

 

[Pariah]

"Ok, since Firewire is connected usually by a card off of the ide bus, then it has to transfer data at ide rates, but this can nowhere meet the max potential to firewire."

I don't understand what you are saying here, can you clarify that? Current ATA tech is capable of up to 100/133 MB/s, while firewire is limited to 50MB/s.


"We're only really going to see about 15MB/s going by cable to the card through the ide bus"

I don't understand this either. Where are you getting 15? The IDE bus doesn't really play any limiting part in this traversal of data. Basically, the data comes off the drive and has to go through an IDE-firewire bridge. This step is the performance limiter. The best bridges currently allow for 30-35MB/s no matter how fast the IDE drive. This is not a firewire limit, nor an IDE limit, it is simply the limit of the bridge between them.

"This is not getting anywhere near 400 Mbits/s, so until there's some spec changes to how Firewire is implemented (like directly on the mobo with it's own separate bus), then it will still operate like ide and will not even touch SCSI speeds. "

The bridge is the limiter, not the firewire implementation. If there was a zero penalty bridge, there are a few IDE drives (WD BB series, IBM 120GXP) that are capable of right around 50MB/s which is the theoretical firewire limit, real world is lower. IDE is not the limiter here, though it is true that even theoretically, a firewire drive can't be faster than an IDE drive, because they are the same drive, you can't be faster than yourself.

"Theoretically, Firewire has the potential of exceeding the fastest Scsi."

How do you figure? SCSI has all the features of firewire, hotswappable, etc..., and is capable of 160MB/s externally, more than 3 times faster than firewire. The knock on SCSI is cost.