Good or Bad Idea To Install Hybrid HDD?

Towelie

New Member
Hi all,

Not been on here for ages as the trusty Humax and custom firmware has been running hassle free for a couple of years now but my stock 500GB HDD is beginning to give up the ghost and needs replacing.

I was just going to get a bog standard 3.5" 1TB drive but I back up pretty much all of my programs and crop all of my recordings which takes a while so was thinking a Hybrid drive would be faster so could possibly crop quicker?

I may be way out and it's not the HDD that is the bottleneck for speed in the cropping process but it was just an idea before I upgrade the drive anyway so was wondering what some knowledgeable people's opinion on this would be?

I did have a search in here but nothing returned so hope this hasn't been covered before but would be nice to know the pros and cons, if any, of using a hybrid drive as opposed to a standard one.

Thanks in advance and happy new year to all!
 

Ezra Pound

Well-Known Member
I'm wondering if you would see much speed advantage in fitting a Hybrid drive into the Humax, I though you only saw a benefit when certain commonly used functions such as boot files etc. were stored on the SSD part of the drive, leaving the HDD to store the less frequently accessed data, but I'm not sure how this would be achieve on the Humax
 

Black Hole

May contain traces of nut
I don't know much about SSDs or hybrids - do they look like ordinary drives on the SATA interface? If not, the standard Humax OS wouldn't work with it.
 

MartinLiddle

Super Moderator
Staff member
I don't know much about SSDs or hybrids - do they look like ordinary drives on the SATA interface?
As far as I know they look like ordinary drives at the SATA interface. Whether using a pure SSD or a hybrid would give a significant performance advantage I don't know.
 

keithatrochdale

Super Moderator
Staff member
It would be a waste of money, the hybrid drives have software that decides what you are using often and moves it onto the SSD and thus gives a speed increase.

.
 

Black Hole

May contain traces of nut
have a look here for an explanation
OK, got it.

The HDR-FOX is already running a pseudo-hybrid scheme, in that the static OS files are stored in Flash. It's hard to see how fitting a SSHD in place of the existing HDD would offer any advantage - you would want the solid state cache to hold many-read-few-write files, and they are already in the Flash.
 
OP
T

Towelie

New Member
Cheers for the replies people, think I will just pop a standard drive in there then. Only thought of it as it was the done thing to do with the PS4s to improve performance loading games etc so thought it may speed up some of the more timely processes I do on the Humax like un encrypting and cropping.

One last question though, would there be any advantages/disadvantages to using a 2.5" drive instead of 3.5"?

Trail of though it 2.5" would generate less heat and stop triggering the fan so much and also may be quieter in general than a 3.5" as that is annoying too. Guessing it could possibly be slower than a 3.5" drive so could make un encrypting and cropping even longer!?

Ta
Matt
 

Black Hole

May contain traces of nut
2½" drives are compromised to fit the small form factor required for notebooks and the like. Stick with 3½".
 

Scrat

May contain acorns
So, is it true you can just slot a standard PC drive in there now? I thought they had to be special DVR-type ones?
 

Black Hole

May contain traces of nut
AV drives are optimised for sequential access of large data files and a high duty cycle. Normal drives are optimised for random sporadic access. A PC drive should work, but would have to work harder than an AV drive.
 

kev7378

Member
Thanks for your input Black Hole :)

I assume that something like

http://www.ebuyer.com/340651-1tb-64mb-sata-6gb-s-intellipower-wd10eurx

would be optimal given what has been said?
I have recently installed the 2TB version of that drive (WD20EURX: WD AV-GP Enterprise 2TB 3.5 inch SATA Internal Hard Drive); no problems so far. It is not in the "lounge" machine so it has not seen "heavy use".

As far as "solid state hybrid drives" are concerned and as far as I understand the current tech. - I don't think the current "solid state hybrid drives" would benefit PVR usage that much as it is regularly read static data that is cached in the NAND flash memory. The NAND flash memory suffers from "wear" as it is rewritten, so regularly writing to it wears it out. A pure solid state drive would be speedy because it only has NAND flash to write to; but would be expensive. The hybrid and solid state drives use algorithms to help reduce the effect of the wear http://en.wikipedia.org/wiki/Wear_leveling.
 

AndrewB

New Member
According to the article on Wikipedia, SSHD drives implement the caching algorithm on-board, so would present themselves as a normal single SATA drive to the host. I've not found any detailed technical information though, so some of this is conjecture...

Can anybody give some details on how the Hummy treats the timeshift buffer file?

If it tends to write to the same blocks of a fixed file - much how a PC pagefile does - then theoretically a SSHD might place the timeshift buffer in the SSD portion because it's a frequently accessed file (or blocks). I wonder if that would enable it to spin down the disc while watching TV either live or time-shifted; only spinning it up for recording or playback?

I need to change my drive shortly for some more capacity. I'm wondering whether to put the theory to the test. I don't know if the Seagate "video" optimised drives (which seemingly are closest to the Humax OEM one in spec) are exactly the same as their SSHD ones though, so I don't know whether it's just adding extra risk for no benefit.

Any thoughts?
 

MontysEvilTwin

Well-Known Member
Can't answer your tecnical questions, but would the option you are considering be cost effective? I recently installed one of these. £35 per TB seems quite good. This drive is very quiet in operation.

Edit. I just looked and the same company has a 2TB Seagate SSHD for £81: a lot cheaper than I had imagined.
 
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Trev

The Dumb One
Why on earth would you want to put a very expensive SSD or even an SSHD into something that is not speed limited by conventional HDD performance?
 

Black Hole

May contain traces of nut
I think the original idea was to eliminate noise and drive wear. SSDs come with their own problems of course. £81 sounds like a good price, prices must have come down significantly.
 

Trev

The Dumb One
I think that the £81 is for a hybrid drive which will possibly not fix the noise side of things as there are still disks spinning and heads 'thrashing' :)
 

MartinLiddle

Super Moderator
Staff member
Can anybody give some details on how the Hummy treats the timeshift buffer file?
As far as I know it is an ordinary file of a fixed size and will only change location if deleted when it will be recreated.
If it tends to write to the same blocks of a fixed file - much how a PC pagefile does - then theoretically a SSHD might place the timeshift buffer in the SSD portion because it's a frequently accessed file (or blocks). I wonder if that would enable it to spin down the disc while watching TV either live or time-shifted; only spinning it up for recording or playback?
I don't know whether it will be cached and I would guess that different makes and models will use different algorithms so there is no guarantee. I did a quick check and the Seagate hybrid drives I looked at have a higher spin speed (7200rpm) than the equivalant drive intended for a PVR (5900rpm). The hybrid drives will also lack some of the PVR optimisations.

The idea is interesting but the aim of the hybrid drives is to increase performance and the PVR drives are not a limiting factor in the Humax, so you don't achieve much for a risk of other problems. Very interested to know how it works out if you do go down the hybrid route.
 

MartinLiddle

Super Moderator
Staff member
SSDs come with their own problems of course. £81 sounds like a good price, prices must have come down significantly.
The OP was talking about hybrid drives that combine a conventional rotating drive and a smallish (8GB for the drives I looked at) SSD with the controller software deciding what goes where. Pure SSD drive continue to drop in price but a 1TB SSD drive is still of the order of £300 so it will be a few years yet before they reach a price point where they are an economic choice for a PVR (although I am sure that day will come eventually).
 
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