Two Hard drives, different speed question. 1

[hopper33]

Noob Question.

I may install two hard drives. One with 10K RPM and the other with 7200RPM. The 10K will have the OS and mainly games, while the 7200 is just for storage.

Will the slower HD effect the speed of the 10K?

A while back I was told that you are stuck to teh speed of the slower HD, but I do not remember if that was said with this particualr configuration in mind.

Thanks for the help!

 

[rvnguy]

hopper33,

When installed as discrete drive units each has it's own access speed.

I believe that what you might have read about, is when using dis-similar drives in a RAID Array you are reduced to the lowest common denominator.

Hope This Helps

rvnguy
"I know everything..I just can't remember it all

 

[hopper33]

Thank you.

I was wondering if that was where I was hearing it!

 

[RICHINMINN]

hopper33,
Are these drives IDE (a.k.a PATA) or SATA?

If they are IDE drives and they are both installed on the same IDE channel (primary or secondary), both drives' throughput will be limited to the throughput of the slower drive. For example, if one of the drives is ATA-133 and the other is ATA-66, BOTH drives will transfer data at the ATA-66 speed (66 Mbps). If you move the slower of the two drives to the secondary IDE channel (which may be where the CD or DVD drive is already located), that drive will be limited to the throughput speed of the CD/DVD drive, which is probably ATA-33 (or lower). But this reduction in speed will probably not be as noticeable, since this drive won't be used for booting the OS or running applications. The time difference in loading or saving files on this drive is negligible, unless you're dealing with HUGE files.

If these are SATA drives, they shouldn't affect each other.

Rich (in Minn.)

 

[garebo]

I have heard this argument before, that with ide drives, the speed of each drive will be what they are supposed to be, providing you are using the correct ide cable (ultra ide 80 wire) in the case of faster drives.
RICHINMINN says its not so.
So which is correct?
My bet would be that if the correct cable is used, the 10,000 will work at that speed and the 7,200 will work at that speed, both on the same ultra ide cable.




Good advice + great people = tek-tips

 

[RICHINMINN]

What speed are you referring to? Neither drive will have its rotational speed (10000 RPM or 7200 RPM) slowed down no matter where it's installed. What IS affected is the data throughput, the amount of data moved per second by the disk controller, the ATA rating. If you use an 80-conductor cable for a higher-speed (ATA-66, -100, or -133) drive, you can achieve its maximum rated throughput, PROVIDED THERE IS NO SLOWER DRIVE INSTALLED ON THE SAME IDE CHANNEL. (If you use a 40-conductor cable, the fastest you can go is ATA-33, no matter whether there is 1 or 2 drives on that IDE channel.) If the controller has to slow itself down to communicate with, for example, an ATA-33 drive on either IDE channel, it communicates with both drives on that channel at the same reduced speed, even if the other drive is capable of communicating at a higher speed (ATA-66, -100, or -133). That is one of IDE's shortcomings that was corrected in SATA controllers.

Rich (in Minn.)

 

[garebo]

If you have the 10000rpm and the 7200 rpm on the same ultra cable, and you are, say, downloading from the net to the 10000, provided that the net connection will allow it, then wouldnt the 10000 rpm drive run at its rated speed?


Good advice + great people = tek-tips

 

[rvnguy]

All,

I stand by my original post.

This is an old limitation generally caused by the PIO mode of transfer. Under the current 'Busmaster' topologies (DMA), transfer mode is set for each device independantly.

To check this, use a disk transfer rate application and you will see that each drive will have a different transfer rate. This is assuming they are different.

rvnguy
"I know everything..I just can't remember it all

 

[garebo]

I, for one, appreciate the posts and having a chance to learn more. I dont really care who is right, wrong, half-right, whatever, and i am not trying to single anyone out, i just like to learn.


Good advice + great people = tek-tips

 

[rvnguy]

garebo,

Just trying to provide what little I can remember.

Hey you gotta have one of those HD speed diag apps?

Try it out and see

rvnguy
"I know everything..I just can't remember it all

 

[garebo]

I am gonna do that when im not so lazy, i guess. I was hoping someone who just give me the answer. But it appears we have different opinions. That means i may have to get off my lazy a..!


Good advice + great people = tek-tips

 

[hopper33]

I ordered them from Dell (getting PC mainly for gaming purposes) and they are Serial ATA. However, I do not know what brand they will be, nor what cables they will use.

One 80GB Serial ATA Hard Drive (10000RPM) and one 160GB Serial ATA Hard Drive (7200RPM) w/ Native Command Queuing.

Thanks for the information!

 

[Freestone]

This guide, though somewhat old, has loads of good PC information. Regarding the same cable, different drive speeds see Independent Master/Slave Device Timing

http://www.pcguide.com/ref/hdd/if/ide/conf_Timing.htm

 

[rvnguy]

hopper33,

I/we have been discussing the IDE interface. As your drives are SATA and you intend to install them as separate drives (not RAID), you will have no problems. Each drive will access at it's own data rate.

Freestone

Thank you for the link. It backs up what my memory could recall in that this was an old MFM and/or PIO mode limitation.

garebo,

Take note of freestone's link...straight forward description.

rvnguy
"I know everything..I just can't remember it all

 

[hopper33]

Thanks everyone for the help!

Is Serial ATA and SATA the same thing, just different ways of saying it?

Also, since this will be a new PC I only imagine Dell will use the correct newer cables for the different speed Hard drives, or PIO modes (what the article was referring too).

 

[garebo]

Yes, serial ata and sata are the same.

I dont buy machines, i build my own and i dont think i would ever buy one already built. As much as Dell makes a good machine, they often also use proprietary motherboards and power supplies. That means you cant use any other motherboards or power supplies as Dell has theirs wired different and they arent generic. I dont like that practice as it severely limits your choice of replacement motherboards and power supplies and some upgrades.
I have heard that some Dell pcs are now using standard parts all the way thru, so you might want to check on that and contact Dell on that, see if any current machines have generic motherboards and power supplies. Just my opinion.


Good advice + great people = tek-tips

 

[hopper33]

So, nowadays, would independant timing be standard?

Thanks again for your help!

 

[garebo]

I dont know what you mean by that?
Are you asking if sata hard drives each use their own rated speed? If so, then i believe the answer is yes.


Good advice + great people = tek-tips

 

[rvnguy]

hopper33

So, nowadays, would independant timing be standard?

Yes, current pratice on newly designed/produced motherboards, BIOS, chipsets, combined is to allow for an covention called bus mastering that incorporates setting each device in BIOS, "AUTO" is the default choice.

If you are matching newer stuff with older, you must take care in what these devices are and where they are conected. If you are using relatively recent stuff or purchasing new, check specifications. Most all devices, even CD's/DVD's can be set as DMA vs PIO.

PIO is the predecessor and is only present, mostly, in older hardware.

rvnguy
"I know everything..I just can't remember it all

 

[rvnguy]

hopper33,

PIO is the predecessor and is only present, mostly, in older hardware.

Clarification:When I stated "present" I should have said something like normal. As most all devices can be forced to PIO mode if necessary with a large hit on speed.

rvnguy
"I know everything..I just can't remember it all