Capacity and HD performance

CyNics

Senior member
Dec 28, 2001
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Does the capacity of a hard driver has anything to do with its performance ? Higher capacity = better performance ?
Thanks
 

Woodchuck2000

Golden Member
Jan 20, 2002
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There's no direct correllation between performance and size.
The main things to look out for are spindle speed, (5400rpm or 7200rpm - higher is better) connection type (ATA-66, ATA-100, ATA-133 - higher is generally better) and cache size (again higher is better, maximum for ata devices is normally 8mb)
 

AndyHui

Administrator Emeritus<br>Elite Member<br>AT FAQ M
Oct 9, 1999
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Higher capacity does equal better performance, when the areal density of the platter increases.

So for a 15GB platter as opposed to a 20GB platter, the 20GB should perform better at 7200RPM, as the data is packed closer together, so the head has less distance required to move.

If anything, any ATA speed above ATA66 WILL NOT affect performance, as that is not where the bottle neck is.
 

sharkeeper

Lifer
Jan 13, 2001
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I have a 400BB with a single 40GB platter that has *identical* performance to a 1200BB!

Cheers!
 

AndyHui

Administrator Emeritus<br>Elite Member<br>AT FAQ M
Oct 9, 1999
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That's correct. Both drives use the same platter.
 

sharkeeper

Lifer
Jan 13, 2001
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<< That's correct. Both drives use the same platter. >>



The original 400BB used a pair of 20GB platters. It was still a great performing drive but had nowhere near the ~50MB/S outer track read performance of the 40GB/platter version! Newer 800BB's *may* be using a pair of 40GB platters as well. My main rant with WD is they give no indication whatsoever in the serial numbers or model numbers.

You can clearly see the difference when an older 400BB and newer 400BB are compared side by side.

Cheers!
 

CyNics

Senior member
Dec 28, 2001
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<< There's no direct correllation between performance and size.
The main things to look out for are spindle speed, (5400rpm or 7200rpm - higher is better) connection type (ATA-66, ATA-100, ATA-133 - higher is generally better) and cache size (again higher is better, maximum for ata devices is normally 8mb)
>>


In storagereview.com if u check their database section, 80GB hd performs better than 60GB, same series and same platter. Why ? just curious.
 

GoSharks

Diamond Member
Nov 29, 1999
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<< In storagereview.com if u check their database section, 80GB hd performs better than 60GB, same series and same platter. Why ? just curious. >>



a larger drive of the same series will perform better than a smaller drive, becuase on the larger drive, when you load up the data, it will store it closer to the outside edge of the disk (higher transfer rates) when compared to the smaller drive...

This may help explain
 

CyNics

Senior member
Dec 28, 2001
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<<

<< In storagereview.com if u check their database section, 80GB hd performs better than 60GB, same series and same platter. Why ? just curious. >>



a larger drive of the same series will perform better than a smaller drive, becuase on the larger drive, when you load up the data, it will store it closer to the outside edge of the disk (higher transfer rates) when compared to the smaller drive...

But they are using the same platter isn't it ? so evern smaller size the data will store closer to the outside edge of the disk too right ? cause same platter.
 

GoSharks

Diamond Member
Nov 29, 1999
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<< But they are using the same platter isn't it ? so evern smaller size the data will store closer to the outside edge of the disk too right ? cause same platter. >>



same type of platter, yes, but with more sides/platters in use. say you have a 40gb hard drive with 1 platter and 2 heads (one on each side). if you were to put 40 gigs of data on it, you would fill up the whole drive all the way to the inside diameter. if you had a 120gb drive with 3 platters, that same 40gb of data would be distributed across the outside diameters of the 3 platters meaning that that data would spin by the heads faster than they would if the data was on the inside.

dunno if that makes sense....

basically, it comes down to where the data is being stored and that outside locations give you better transfer rates than if the data were to be stored on the slower interior.

not to mention there are seek times to be factored in on the larger drives. now i dont know how much the extra heads on the arm affect the times (not enough to show in the specs), but theoretically on a larger drive, if you have the same amount of data on that and a smaller one, the larger drive will give you better seek times. the arm will not have to move as far on the larger drive, as the data is in a smaller area on the axis on which the arm moves on. if your arm was on the outside of the platter/drive, and it was asked to acess the 40gb mark on a 40 gb drive, it would have to move all the way to the inside, whereas on a 120gb drive, it might only have to move 1/4th the way.
 

CyNics

Senior member
Dec 28, 2001
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So is there a big diffs (performance) between a 20GB maxtor hard drive and 80GB WD hard drive, same series ?