Internal HD

[wadleigh]

I am looking at getting an internal HD to store all of my stuff and then use my USB HD as the backup. I saw the

following specs on the Western Digital HD and do not understand what it is saying - see below and the link that

contains the info.

 

Performance

Drive Transfer Rate 300 MBps (external) / 106 MBps (internal)

 

http://www.pcuniverse.com/WD-Caviar-Black-WD7501AALS-Hard-drive-750-GB-internal-3.5-SATA-300-

/WD7501AALS/20PK/pd/p4673749

 

This is an internal HD. So how can it be faster when it is external??? Isn't it always faster when the HD is internal?

Or am I understanding this incorrectly?

 

Thanks,

John

[wadleigh]

This link works...

 

 

 

http://www.pcuniverse.com/WD-Caviar-Black-WD7501AALS-Hard-drive-750-GB-internal-3.5-SATA-300-/WD7501AALS/20PK/pd/p4673749

[wadleigh]

Here is a better example. Here are two different HDs and each have different "Maximum Internal Transfer Rates" (175Mbps versus 145Mbps).

 

"http://www.buy.com/prod/samsung-spinpoint-f1-hd753lj-hard-drive-750gb-7200rpm-serial-ata-300/q/loc/101/208131108.html"

 

"http://www.buy.com/prod/western-digital-caviar-black-wd7501aals-hard-drive-750gb-7200rpm/q/loc/101/208190151.html"

[benbangerter]

Just a guess: the higher speed reflects the transfer rate from the internal RAM buffer of the drive over the SATA link, and the slower speed reflects the transfer rate from the magnetic disk ifself to the RAM buffer.

[bangengeman]

John, typically, internal HDs are connected to the main board of your computer via SATA. SATA specifications have

up to 3.0 giga*bits* per second of data transfer (after some math, it comes out to 300 mega*bytes* per second).

That's how fast it can theoretically transfer the data to/from your HD. In reality though, the speed is still

limited by how fast your HD spins, and that's how they get the internal speed.

 

Most HDs have a 7200 RPM speed, while the expensive ones (the ones designed for most bigger computers) have up to

15,000 RPM. It's a lot of math involved, but there are some things to look out for in HD speed:

 

1. RPM - since most of the time it's 7200, that's not much of an issue.

2. Cache - most of the newer ones come in 8 or 16 or 32 megabytes. The more the merrier.

3. Number of platters and areal density - too difficult to explain, but wikipedia can help clarify.

 

Most computer sites usually list a review of most common or new hard drives. Unless you are a very meticulous

person, HD speeds won't matter much. Although I would suggest looking at tomshardware.com, anandtech.com and

extremetech.com for guides on hard drives. If you ask me, though, get Seagate or Western Digital -- you can't go

wrong with either. Samsung is still new in the market, so reliability is still an issue for me.

[wadleigh]

ok great! thanks! I got an internal HD and it is much faster! problem now is that Lightroom still is a bit sluggish when navigating around the program. Not sure if this is "normal" or not.

 

I have an All-In-Wonder ATI X800 XL video card. How can I determine if this is having performance issues? Is there some way I can determine if its my video card that is the cause of the sluggishness? I would love to eliminate it. I just feel I am sometimes waiting for Lightroom to be catching up to me and it should not be like that.

 

thanks!

[wadleigh]

Real quick - seems also my video card had problems, so I got a new one and things are better now. The new internal HD also has been helping a lot.