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2TB 7200rpm vs 2x1TB 5400rpm RAID 0?

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I'm in a dilemma here, I'm wondering if you guys can decide for me.

I bought a laptop that comes with 1TB 5400rpm drive. I'm planning to replace it with a SSD and find an use of 1TB drive for something.

I do video editing specifically and only fastest connection I have on my laptop is USB 3.0, so I'm looking forward to get the fastest speed possible.

So I thought of buying another 1TB 5400rpm drive and combine to get a 2TB RAID 0 setup, buy an enclosure to use via USB 3.0.

Or, I will just sell the 1TB on Craigslist and get 1 2TB 7200rpm drive with USB 3.0.

So,

2TB 7200rpm VS 2x1TB 5400rpm RAID 0, who's the winner?

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Hi Guys, it's good to know that theirs a forum about RAID and hard disk expertise. anyways i had raided a 5 2TB Hard disk with a RAID 5 Level and NTFS file systems on windows 7 using intel raid. we had encountered some situation; there are two system access on this drive one is on WRITE and one is on READ. when this two system accessing this drive at the same time one of system will experiencing slow it terms of reading. by the way we use this workflow for editing station. any idea why this raided drive is showing this kind of behavior. it does it means that the hard disk head cannot do read and write at the same time?

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I'm in a dilemma here, I'm wondering if you guys can decide for me.

I bought a laptop that comes with 1TB 5400rpm drive. I'm planning to replace it with a SSD and find an use of 1TB drive for something.

I do video editing specifically and only fastest connection I have on my laptop is USB 3.0, so I'm looking forward to get the fastest speed possible.

So I thought of buying another 1TB 5400rpm drive and combine to get a 2TB RAID 0 setup, buy an enclosure to use via USB 3.0.

Or, I will just sell the 1TB on Craigslist and get 1 2TB 7200rpm drive with USB 3.0.

So,

2TB 7200rpm VS 2x1TB 5400rpm RAID 0, who's the winner?

In short, RAID-0 will double the transfer rate of the drives. The rest of the performance-related attributes remain pretty much the same as the single drive.

Therefore:

Transfer rate: 2x1TB 5400 > 1x2TB 7200 (about 50% faster rough guess)

Access time: 2x1TB 5400 < 1x2TB 7200 (about 33% slower rough guess)

All these, if we compare 5400 to 7200 "apples to apples". This means that we compare platters of the same size, the same cache memory size, same drive size(external inches) and other minor tweaks.

- The size of the platter is important and can significantly affect performance (the more GB the platter has, the faster the drive. EG, an 7200 RPM 2TB drive with 2 platters of 1 GB will be significantly faster than an 7200RPM 2TB drive with 4 platters of 500GB)

- 2,5 and 3,5 inch drives are not comparable performance wise either. 3,5 inch drives have faster transfer rates

Now, if your 1TB 5400 drive is from your laptop it'll be a 2,5 inch one. AFAIK, there is no 2,5 inch 2TB 7200RPM drive, so if you mean to compare a RAID-0 of 2 5400RPM 2,5 inch HDDS with a single 3,5 inch 2TB 7200 drive, then the latter is the faster one everywhere.

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It depends on the workload and the stripe size. For random IO, there are cases where the single drive would be faster than two slower drives in RAID0.

I'm a mostly random-IO kind of guy :-) but my guess is that for sequential IO (eg you're never editing more than one video at a time, and your editing setup doesn't involve writing results to disk at the same time as it's reading), the two drives will be faster *assuming* apples-to-apples like orion24 mentioned.

But all the considerations orion24 mentioned also come into play.

My opinion, don't try to use the laptop drive for this workload. Get a good fast 3.5" drive and if you need more speed later, add more (you're thinking of using RAID0 so to me this means you don't care about the data on the disks - eg this is temp space and your real storage is elsewhere, so it should be no problem to change that single drive into a RAID0 later and re-populate it).

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It also sounds like you might be considering having half a stripe set on an external USB drive - this is not a great idea.

If you have to use 2.5 inch 5,400 rpm drives, I understand the lower profile WD drive is faster than the thicker one.

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- The size of the platter is important and can significantly affect performance (the more GB the platter has, the faster the drive. EG, an 7200 RPM 2TB drive with 2 platters of 1 GB will be significantly faster than an 7200RPM 2TB drive with 4 platters of 500GB)

Since you mentioned it, could you please explain me why? If the density is lower, the linear transfer rate is lower as well, I know. However, I would expect the data to be striped among platters! that would increase again the transfer rate.

Where is the mistake?

Thank you.

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Since you mentioned it, could you please explain me why? If the density is lower, the linear transfer rate is lower as well, I know. However, I would expect the data to be striped among platters! that would increase again the transfer rate.

Where is the mistake?

Thank you.

Hi Olaf,

the thing with striped data is that the chance of it to be on the very same position of the head is very low, therefore the whole arm has to move all heads on a different area to "fetch". And another consideration is that the firmware has to spend some cycles to sync the commands to the heads to fetch data from different areas and build the logical unit that is requested.

I am absolutely positive that a storage engineer that writes firmware for drives will explain that in much greater detail, so I hope that someone comes along :)

Cheers,

SV

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