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Am I Missing Hard Drive Space?

Last response: in Storage
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April 6, 2006 3:59:16 AM

I just put together an external hard drive. It is a Seagate 200 GB ultra ATA/100. I put the drive into a Mad Dog usb2.0/firewire enclosure.

I am running windows xp home edition with SP2

I used the windows disk management and launched the "new disk wizard".

It walked me thru the process without a hitch.

My question is: Why is this hard drive seen as 186 GB ? [It is a 200 GB drive] Why am i missing 14 GB's ?

Also, Is usb 2.0 preferred over firewire? I have both connections on my computer. Which should i use?

I formatted in NTFS with just one primary partion.

thanks for your help.......

burt
April 6, 2006 4:07:33 AM

Quote:
I just put together an external hard drive. It is a Seagate 200 GB ultra ATA/100. I put the drive into a Mad Dog usb2.0/firewire enclosure.

I am running windows xp home edition with SP2

I used the windows disk management and launched the "new disk wizard".

It walked me thru the process without a hitch.

My question is: Why is this hard drive seen as 186 GB ? [It is a 200 GB drive] Why am i missing 14 GB's ?

Also, Is usb 2.0 preferred over firewire? I have both connections on my computer. Which should i use?

I formatted in NTFS with just one primary partion.

thanks for your help.......

burt


Because Disk Manufacturers are jerkoffs and advertise values based on 1000Byte vs. 1024Byte. Your drive 200GB getting 186GB is normal, on average, take the GB the manufacturer says (e.g., 200GB) and subtract 7% from it, that's average what you lose. Some drives lose less (I have drives as low as 5%) and some lose more (some high as 9%).

200GB - 7% = 186GB

I always use USB 2.0, 2.0 is 480Mbps vs. 400Mbps on Firewire (There are 800Mbps Firewire, but good luck finding a mobo and external enclosure that supports it for under a bajillion dollars).

~~Mad Mod Mike, pimpin' the world 1 rig at a time
April 6, 2006 5:19:45 AM

As MadModMike said, its the difference in how gigabytes are calculated. As for USB 2.0 vs Firewire... Firewire is faster believe it or not. It has to do with how data is transfered over the bus. USB has to put the data into packets before it can send them while Firewire just streams the data as is. The result is that Firewire is much more efficient, though neither lives up to their advertised bandwidth. 400Mbps=50MB/s and 480Mbps=60MB/s. I don't have links for this anymore... you're all resourceful... I'm sure you could Google it if you dont believe me.
I have a Seagate 7200.7 in... well... lets just say its attached to a Firewire/USB 2.0 to ATA converter. It used to be a Seagate external HD, but the original drive died so I ripped it appart and attached the 120GB to the controller inside. Anyhow, the drive used to average a bit over 40MB/s for the entire drive when I had it installed internally. When connected via USB 2.0 it gets *in the 20s*. When connected via Firewire it averages about 10MB/s faster and has slightly better seek times. I lost my data sheet and will run benches in a minute so I can give some actual numbers.

-mcg
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April 6, 2006 5:40:54 AM

Firewire and USB are both Serial Based, I would blame the USB 2.0 Serial Controller for USB 2.0 lacking in computers, and that Firewire was designed as a SCSI replacement, and USB 2.0 was designed just for simple connections.

~~Mad Mod Mike, pimpin' the world 1 rig at a time
April 6, 2006 5:56:29 AM

Hmm... coulda sworn I'd read something about USB using packets and whatnot somewhere. Anyway, here's the data I gathered using HD Tach:

USB 2.0: random access 15.3ms, Avg read: 22.9 MB/s, burst speed: 29.1 MB/s

Firewire: random access 15.0ms, Avg read: 31.0 MB/s, burst speed: 40.4 MB/s

Also: just Google'd up "firewire vs usb" (without the quotes) and got this:
http://www.usb-ware.com/firewire-vs-usb.htm
This article is older, but shows pics of transfer diagrams:
http://www.digit-life.com/articles/usb20vsfirewire/

-mcg
April 6, 2006 5:58:23 AM

Quote:
Hmm... coulda sworn I'd read something about USB using packets and whatnot somewhere. Anyway, here's the data I gathered using HD Tach:

USB 2.0: random access 15.3ms, Avg read: 22.9 MB/s, burst speed: 29.1 MB/s

Firewire: random access 15.0ms, Avg read: 31.0 MB/s, burst speed: 40.4 MB/s

Also: just Google'd up "firewire vs usb" (without the quotes) and got this:
http://www.usb-ware.com/firewire-vs-usb.htm

-mcg


"Hi-Speed USB 2.0 uses a "Master-Slave" architecture in which the computer handles all arbitration functions and dictates data flow to, from and between the attached peripherals (adding additional system overhead and resulting in slower data flow control)" - Exactly what I was talking about. It's like SATA vs. IDE.

~~Mad Mod Mike, pimpin' the world 1 rig at a time
April 6, 2006 6:13:42 AM

i always though firewire was faster


ehh lets not debate
April 6, 2006 6:18:18 AM

I guess its what I was talking about too :oops:  Its been years since I've read up on that stuff.

-mcg
April 6, 2006 9:53:09 AM

@MadModMike: SATA vs IDE, with USB2 being (more or less) IDE (due to master/slave control) and Firewire being SATA.

On sustained data streams, Firewire is better than USB2 - in most cases. MMM is right to point out that the logic is very important in this equation, though: a good USB2 controller (with no other devices connected on it) will run MUCH faster than a run-of-the-mill USB controller. Due to it being one-to-one connection, Firewire doesn't involve as much overhead as USB does - it is more stable performance-wise.
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