Hey,
I have a software raid5 array that consists of 3x1 TB HDDs. I recently replaced one old 5400 rpm drive with a WD blue 7200 rpm and I noticed an odd drop in speeds at the end of every write session. Just out of curiosity can anyone explain this phenomenon.
Here is a benchmark of the raid array. Odd thing but I'm pretty sure that the seq write results were far better on the old setup.
What are the rest of the drives in the array?
What is the controller?
If you do a really large read, do you have the same problem?
The array consists of a 1TB Seagate 5400 rpm, an old 1TB Samsung 5200 rpm and the new WD blue at 7200 rpm. They are all drives I salvaged from external USB enclosures.
There is no controller, it is a windows 10 ''parity'' setup.
I never encourted any problems regarding read speeds both on the machine and over my local network.
AFAIK the write speed will be limited to the speed of the slowest drive. You really should be using identical drives
Thanks for your reply but I am pretty sure that my write speeds got worse after I put in a faster drive. I am in the process of upgrading my storage and I would like to kindly ask you if you have any leads on a couple of affordable and reliable 4 TB HDDs. Shops based in EU preferably.
Not sure about the EU - but if you can get your hands on some HGST drives they are really good.
As for the write speeds, as it is a cpu bound task without a RAID card, the more drives, the higher the cpu demand. If the drives write at different speeds, then it goes up again because of waiting for the write buffer.
HGST drives must be realy good based on reviews that I read, a bit pricey but seem like good value. I also found some 4TB WD blues @5400 rpm at discount (129$ US) that could suit my needs. I guess I will have to live with my obscure ''parity'' solution for now and wait till prices drop some more. Thanks again for your answers.
Just something to remember, raid 5 should not be used with drives that are really larger than 2TB, so just for future reference, I recommend you plan on going raid 6 if you want to use 4TB drives.
Do you have write caching enabled? Its probably just slowing down as it writes out the cache to disk. Don't know what it got slower though.
Point taken. Other than that my plan is to use a raid 1 config in the new array.
Write caching is enabled so it could have something to do with that too.