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My Humax Forum » Freesat HD » HDR 1000, 1010, 1100S

31. 

    grahamlthompson
    

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    Martin Liddle - 1 hour ago  » 

    grahamlthompson - 35 minutes ago  » 
    2 The Time Shift Buffer file is continously being overwritten all the time the pvr is on, so is likely to cause issues much sooner than a conventional hard disk.

    Do you have any figures to back up that assertion? This article http://techreport.com/review/27436/the-ssd-endurance-experiment-two-freaking-petabytes suggests a 256GB drive will have a life time write capability of more than 500TB of data.

    Does that include a continous rewrite of the same file say 8hrs every day. In any case what use is a 256GB drive as a primary storage drive for a PVR, and what advantage does it have over a conventional drive
    (other than power consumption) ?

    It seems the time shift buffer file needs to remain on the same place on the disk. Sure you can delete and recreate but you will lose the contents.

    The OP wants over 2TB of storage and then suggests SSD drives. Does not compute.

    Estimates please for a 3TB SSD drive ?

    | Sat 3 Oct 2015 20:51:11 #31 |
32. 

    atacama40
    

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    performance issue aside (which I can't honestly say I understand just yet) is it even possible to implement an SSD.....of any size? btw no I don't see any 3TB SSD yet....have put a couple of 1TB's in.

    I've installed a number of SSD's om laptops and desktops with very favorable effects. But curious if it's even possible on a technical basis?

    I have to plead guilty to just likeing the 'upgrade mentality' .... do I need it? Probably not but when did that ever stop a tech impulse?

    | Sat 3 Oct 2015 21:05:30 #32 |
33. 

    atacama40
    

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    In fairness my main interest in the 1100S is the DNLA connection to my QNAP NAS....it's large and has a lot of media data. Hoping this aspect is performing well.....storage of a "lot of TV" is in reality secondary for me but it's interesting to understand what is possible.

    | Sat 3 Oct 2015 21:08:02 #33 |
34. 

    grahamlthompson
    

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    atacama40 - 1 minute ago  » 
    performance issue aside (which I can't honestly say I understand just yet) is it even possible to implement an SSD.....of any size? btw no I don't see any 3TB SSD yet....have put a couple of 1TB's in.
    I've installed a number of SSD's om laptops and desktops with very favorable effects. But curious if it's even possible on a technical basis?
    I have to plead guilty to just likeing the 'upgrade mentality' .... do I need it? Probably not but when did that ever stop a tech impulse?

    SSD's are ideal for say a operating system on a PC which has upgrades but no area gets continously thrashed (like the time shift buffer file on a pvr). They can dramatically boost the boot times of a PC, but normally are only used for the operating system. You still need a coventional hard disk to store the programmes and data the OS needs to access.

    Humax pvrs already have the OS in static NVRAM (That's why you can simply swap the hard disk). Modern low power AV drives have the speed to record multiple HD streams and replay multiple HD recordings simultaneously. Even the SATA1 drives used in the old Foxsat-HDR could record two HD streams and stream up to 4 different HD recordings across a home network, why would you need more performance ?

    The limitation on speed is not the hard drives, rather the pvr cpu and memory capability to support the basic pvr functions.

    No matter how fast the storage it's not going to make any difference.

    On a similar vein you often get asked why the USB ports are not USB 3.0. Same answer USB 2.0 is way faster than the the pvr an support already.

    These days HD broadcast bitrates are much lower than they used to be (thanks to improvements in encoders and stat muxing).

    For Example the BBC-HD bitrates are now on average lower than the best SD channels of a few years ago.

    | Sat 3 Oct 2015 21:28:07 #34 |
35. 

    Martin Liddle
    

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    grahamlthompson - 57 minutes ago  » 

    Does that include a continous rewrite of the same file say 8hrs every day.

    Yes. The wear levelling technology in the controllers is designed to cope with exactly that situation.

    In any case what use is a 256GB drive as a primary storage drive for a PVR, and what advantage does it have over a conventional drive
    (other than power consumption) ?

    The main advantage I can perceive would be complete silence; some people (certainly not me) seem very bothered by even the slighest noise from a PVR hard drive.

    It seems the time shift buffer file needs to remain on the same place on the disk. Sure you can delete and recreate but you will lose the contents.

    Sigh we have done this before some months ago; the contents do not remain in the same physical place on an SSD.

    The OP wants over 2TB of storage and then suggests SSD drives. Does not compute.

    I am not advocating the use of SSDs in PVRs but your arguments against them are flawed.

    Estimates please for a 3TB SSD drive ?

    Well you can have a 16TB drive for $7000 if you wish, see http://petapixel.com/2015/08/15/samsung-16tb-ssd-is-the-worlds-largest-hard-drive/

    | Sat 3 Oct 2015 21:56:57 #35 |
36. 

    REPASSAC
    

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    grahamlthompson - 57 minutes ago  » 
    It seems the time shift buffer file needs to remain on the same place on the disk. Sure you can delete and recreate but you will lose the contents.
    

    Martin Liddle - 8 hours ago »

    Sigh we have done this before some months ago; the contents do not remain in the same physical place on an SSD.

    Sorry I don't understand this - For example on the Foxsat this file is created once and is the maximum size possible. It is never deleted and remains in the same position on disk, which if write errors occur within it, gives huge problems. It can only be deleted with the custom firmware installed.

    While we don't know if this is the sasme on the HDR-1x0xS series it is likely.

    The only real advantages of SSD is a minor sound reduction and perhaps a small power reduction (did not check the later point) balanced against a huge cost increase.

    | Sun 4 Oct 2015 6:29:37 #36 |
37. 

    atacama40
    

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    Interesting discussion. I take the view that upgrades should be done rarely unless a total masochist or enjoy tech, but when done, upgrade as far as cost and tech limits allow. This has rarely let me down. Note rarely implies a defined failure rate as well

    So in this case the swap out routine seems straightforward (famous last words) and the price one can source a top spec 3TB is hardly (if any)more than a 2TB, (with a little searching, persistence & the wind in the right direction). Example...I upgraded my NAS from 2TB to 24TB by buying 4 x 6GB red WD's off an ebay guy for about £110 quid a piece...early part of this year..new & as good as it sounded. Boring but point being, the tech is out there cheap and so if poss, why not stuff it in....so long as it works, works as well as original and brings no performance negs. Size as such has a negligible cost hit with a little smart...a generalism of course and there are many quotes about generalisms. Need? Well that's questionable of course.

    The SSD discussion I need to read a few times to get close to properly understanding but many thanks for the data, is useful and interesting.

    Tech considerations aside (important as they are) I'm still curious to know if anyone actually did it and can provide tangible observations as well.

    Again 1TB SSD's can be sourced very cheaply. I've had a few (new & 2nd hand) Samsung EVO Pro think most have beenand all have performed flawlessly either in laptops or in Raid 10 configs in a couple of desktops multi boots.

    Again I mention only as it's a shame to miss the cost/effort sweet spot of upgrade if we have analysis but also observed results of such an upgrade.....size or format wise.

    | Sun 4 Oct 2015 10:08:23 #37 |
38. 

    Martin Liddle
    

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    REPASSAC - 4 hours ago  » 

    grahamlthompson - 57 minutes ago  » 
    It seems the time shift buffer file needs to remain on the same place on the disk. Sure you can delete and recreate but you will lose the contents.
    

    Martin Liddle - 8 hours ago »
    Sigh we have done this before some months ago; the contents do not remain in the same physical place on an SSD.

    Sorry I don't understand this - For example on the Foxsat this file is created once and is the maximum size possible.

    An SSD has a very smart wear levelling controller which operates such that at the SATA interface the blocks appear to be at the same location but internally they are shuffled around to equalise wear.

    | Sun 4 Oct 2015 10:39:35 #38 |
39. 

    Martin Liddle
    

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    atacama40 - 32 minutes ago  » 
    Tech considerations aside (important as they are) I'm still curious to know if anyone actually did it and can provide tangible observations as well.

    I don't recollect anybody reporting doing it. Also it isn't clear to me whether the Linux kernels used on the various boxes have SSD support included. I think at some point in the future we will see SSDs in PVRs but I wouldn't advocate doing it now.

    | Sun 4 Oct 2015 10:43:27 #39 |
40. 

    REPASSAC
    

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    Then there is the SSD or SSHD question.
    SSHD has a price advantage over SSD but is slower then SSD (According to Seagate)
    http://www.seagate.com/internal-hard-drives/solid-state-hybrid/desktop-solid-state-hybrid-drive/?sku=ST1000DX001

    Look at the price comparison between HDD and SSHD.
    http://www.amazon.co.uk/Seagate-STCL4000400-4000-GB-Internal/dp/B00GY0R5HQ

    | Sun 4 Oct 2015 10:55:08 #40 |

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