U4 HDD Questions?

[MichaelAtOz]

I did a bit of searching but couldn't find much discussion about suitable HDDs for the U4.
So...please excuse the shotgun...

Does the U4 need to have an internal HDD, or can it function with just a USB drive?

I went looking at 2.5" drives, the 7200 RPM drives are limited in capacity, larger ones are 5400 RPM, are they fast enough to cover multi-channel HD recording and playback concurrently? (I presume the U4 can do the reputed 8-10 channel recording the T3/T4 can?)

Can the USB3 port handle a hub with multiple HDDs? (presuming a powered hub)

I note some people are using SSDs, does the firmware implement TRIM?

Consumer SSDs have a lifetime write limit then die, has anyone worked out how much is written by timeshift and HD recordings, so the 'life' of a SDD can be calculated?

Thanks, I'm trying to check all the boxes before ordering a U4 upgrade from my T3.

[MrQuade]

Does the U4 need to have an internal HDD, or can it function with just a USB drive?

It will function just fine without any drive at all. You could point it at a network share if you really wanted to, but it is recommended that you have at least some sort of drive inside to make masic operations like timeshifting work reliably. (prevent against USB disconnections and network outages etc...)

I went looking at 2.5" drives, the 7200 RPM drives are limited in capacity, larger ones are 5400 RPM, are they fast enough to cover multi-channel HD recording and playback concurrently? (I presume the U4 can do the reputed 8-10 channel recording the T3/T4 can?)

Modern 2.5" drives are more than quick enough for that.
There is some discussion as to how the high capacity shingled drives perform, so it may be worth considering sourcing a non-shingled if it worries you. I am running with a shingled drive in mine that I deliberately dirtied up, and it is behaving itself so far.

Can the USB3 port handle a hub with multiple HDDs? (presuming a powered hub)

It can.

I note some people are using SSDs, does the firmware implement TRIM?

It does.

Consumer SSDs have a lifetime write limit then die, has anyone worked out how much is written by timeshift and HD recordings, so the 'life' of a SDD can be calculated?

It's not as bad as you may be thinking. Modern SSDs, particularly larger capacity ones have plenty of write endurance for this purpose.
An HD channel consumes 2-3 GB/hr and an SD channel will be about 1.5 GB/hr. By the time the SSD write endurance is used up, a typical harddisk could have also given up the ghost due to mechanical wear.

[MichaelAtOz]

Thanks, I though I'd do the SSD life horoscope.
Rough worst case end of the spectrum.

EDIT: Assumes deletes are not writes, otherwise halve it.

[prl]

File deletes in the ext filesystem normally only write to a small number of blocks (the block containing the inode, the block containing the directory entry and the free block bitmap blocks that contain the bits for the freed blocks). In the theoretical worst case, each freed block bit might be in a different block of the bitmap, but I suspect that, or even close to that, is very unlikely.

Your Max case numbers are also extremely unlikely; even your Heavy case seems way over likely use to me.

Your Max case would fill a 3TB drive in less than 4 days and your Heavy case would fill the drive in less than 14 days. Even your "Light" case records 12 hours of recordings a day: no-one is likely to do that or be able to keep up watching it. A lot of people would even find your Trivial case, recording 4 hours of programming/day, every day, more than they'd keep up with.

[MichaelAtOz]

I did say "Rough worst case end of the spectrum", & Max was Max because I had to do the theoretical limits.

I probably do more than Trivial ATM, just because I record it, doesn't mean I watch it, I have >2TB of unwatched.
Sort of speculative recording, just-in-case, I archive some stuff, but do a cull every-so-often...YMMV.

[MichaelAtOz]

But 3-7 years is OK.

[wozzzzza]

how do SSD's perform over a HDD? does it do anything like the recording lists faster or anything different to make it worthwhile putting in an SSD instead of HDD??

[MrQuade]

Zero benefit.

[IanSav]

Hi Wozzzzza,

I would suggest that SSDs will likely lighten your wallet but have minimal impact on PVR performance.

Regards,
Ian.

[IanB]

Lighten your wallet, but also zero disk noise. Not that modern AV disk make much noise.

[prl]

But on a U4 you will have fan noise anyway.

[prl]

how do SSD's perform over a HDD? does it do anything like the recording lists faster or anything different to make it worthwhile putting in an SSD instead of HDD??

Loading the media selection screens is one of the few places where an SSD might do better than a HDD in any practical sense.

Disk performance is unlikely to be much of an issue otherwise. Recording has fairly low disk bandwidth requirements. If you record all of a broadcaster's channels at once, it's a total of about 25Mb/s, or a little over 3MB/sec.

[wozzzzza]

cool, staying with a HDD

[MichaelAtOz]

For the record, on the U4 I went with a hybrid drive (2.5") like I had on my T3 (3.5").
On the T3 when I went from a normal HDD to the hybrid I noticed booting & opening the recorded movie list were noticeably faster.
The only down-side is for 2.5" they are max 2TB.

[prl]

A T4 will boot much faster than a T3. Its processor is a considerably faster. The HDD type won't play much role in the boot speed. Booting doesn't do very much to the HDD.

[mrcell]

Just wondering if anyone has feedback on what drives the U4s are shipping with? I remember back in the day there was robust discussion about what "colour" WD drive (or alternate manufacturer) was best for the T3 vs what people were getting if they purchased their T3 with a drive pre-installed. I'm thinking about a U4 with 2GB hdd - aside from a little cash saving, is there any benefit to buying it bare bones and sourcing a drive myself?

[MrQuade]

I'm thinking about a U4 with 2GB hdd - aside from a little cash saving, is there any benefit to buying it bare bones and sourcing a drive myself?

Not really, it's only a cost benefit. I'm not sure exactly what drives the U4 ships with now, but going by history, they will not be anything special that you can't just buy at your local computer shop.

[prl]

My test U4 has a Seagate Barracuda ST2000LM015 installed by Beyonwiz. This was either a a late pre-production or very early production box (it had production packaging). That model is also what's shown in the image in Accessories>Internal hard drive>2.5">Seagate Barracuda 2TB (2000GB) 2.5″ SATA HARD DRIVE.

I'm not sure what Beyonwiz currently ships in U4s or what is actually shipped from the store if you buy a HDD from them as an add-on. It probably depends on availability and price at the time they order stock.

[prl]

Funnily enough, it's slightly cheaper to buy a 2TB U4 from Beyonwiz than to buy a barebones U4 and a 2TB HDD from Beyonwiz and install it yourself

The Seagate Barracuda ST2000LM015 is available from Scorptec for $129, vs $189 for a 2TB HDD from Beyonwiz vs $180 effective price of the HDD if you buy a 2TB U4 (displayed prices only, not including delivery).

Anyway it's roughly a $50 saving to source your own new HDD. YMMV.

[MichaelAtOz]

And the Seagate ST2000LX001 2TB w/8GB NAND FireCuda 2.5" is not that much more and comes with 5 year warranty, v's 2 for the ST2000LM015 or WD Blue.

[Star6key]

And the Seagate ST2000LX001 2TB w/8GB NAND FireCuda 2.5" is not that much more and comes with 5 year warranty, v's 2 for the ST2000LM015 or WD Blue.

I've just bought the above 2.5" ST2000LX001 ($128 delivered from a recent ebay special... not too shabby ) and will install it in my T4. If I do get round to buying a U4, will I be able to restore the settings from the T4 to the U4, or are the 2 fw not compatible?

[MrQuade]

I've just bought the above 2.5" ST2000LX001 ($128 delivered from a recent ebay special... not too shabby ) and will install it in my T4. If I do get round to buying a U4, will I be able to restore the settings from the T4 to the U4, or are the 2 fw not compatible?

They're compatible enough that they should restore, but will cause various subtle problems. Don't do it.

[prl]

They're compatible enough that they should restore, but will cause various subtle problems. Don't do it.

If you use IceTV, definitely don't do it.

[Star6key]

They're compatible enough that they should restore, but will cause various subtle problems. Don't do it.

If you use IceTV, definitely don't do it.

Don't use Icetv.
Meh... still not convinced I need a U4, but the HEVC playback and 1920x1080 hdmi recording would be nice.

[MrQuade]

Meh... still not convinced I need a U4, but the HEVC playback and 1920x1080 hdmi recording would be nice.

Just keep in mind that you are still never going to have a perfect 1 for 1 recording, even with the improved 1080 HDMI recording capability. The U4 still needs to transcode the incoming signal, and you will always get generational compression losses as a result. What you will see is a marginal improvement in image quality with a substantial increase in file size.

The 4K output, HEVC capability and roughly doubled network speeds are a big plus though.

[Star6key]

Meh... still not convinced I need a U4, but the HEVC playback and 1920x1080 hdmi recording would be nice.

Just keep in mind that you are still never going to have a perfect 1 for 1 recording, even with the improved 1080 HDMI recording capability. The U4 still needs to transcode the incoming signal, and you will always get generational compression losses as a result. What you will see is a marginal improvement in image quality with a substantial increase in file size.

The 4K output, HEVC capability and roughly doubled network speeds are a big plus though.

Fair enough.

[mrcell]

It will function just fine without any drive at all. You could point it at a network share if you really wanted to, but it is recommended that you have at least some sort of drive inside to make masic operations like timeshifting work reliably. (prevent against USB disconnections and network outages etc...)

I've pulled the trigger and ordered a U4 after another power supply issue with the T3. I would really prefer to run it without an internal drive so while I take your point about an internal drive making timeshifting more robust, does the U4 support timeshifting to a USB connected drive?

If it does then I would like to try using a USB3 bus powered external drive for timeshifting and recording/playback to see how it goes. If I have any dramas I will try changing the external drive to an independently powered one. If there's still any issue I'll give up and put an internal drive for timeshifting.

[prl]

does the U4 support timeshifting to a USB connected drive?

Yes, provided the drive is formatted as one of the Linux EXT family of filesystems (ext2, ext3 or ext4).

[MrQuade]

If it does then I would like to try using a USB3 bus powered external drive for timeshifting and recording/playback to see how it goes. If I have any dramas I will try changing the external drive to an independently powered one. If there's still any issue I'll give up and put an internal drive for timeshifting.

Either type of USB-connected drive will work fine. You should allow the U4 to format it as ext4 so that the timeshift filesystem tricks work properly.

Some warnings though. I assume that you want an external drive so you can unplug it to access recordings? etx4 will mean that a vanilla Windows PC won't be able to read the drive. Also, the fact that timeshift is running on the USB drive is going to make it awkward to unplug the drive while the U4 is running.

Otherwise, I'm not sure I really understand why you don't want an internal drive.

[mrcell]

Thanks Peter & MrQuade,

I want the external drive for recording/playback because whenever anything happened to the T3 I had to remove the drive before sending it off so that I wasn't at risk of losing the recordings (if it was lost in transit or if the repairer formatted the drive) and so I could watch the recordings some other way while the unit was away. I know it doesn't bother most people but I absolutely hate opening the case and mucking around with hardware. If it's an external drive I can just plug it into another Linux based PVR or run up Linux drivers on my Windows box, grab the video and stream it to the TV. (When everything is running normally I get video on and off the PVR drive with FTP or network shares.)

I want to timeshift to the external drive because if I'm using one anyway (see above) another drive to use internally would be one more I'd have to source. If I do decide to timeshift internally then I'll try to harvest a drive from a 750GB 2.5" external drive I don't use anymore if I can get the USB interface off it but otherwise I'll have to shell out for one.

I'll update this thread to let you know how it goes.

[IanSav]

Hi Mrcell,

I always remove the hard drives before sending anything off for repair. Fortunately removing the Beyonwiz hard drives is not that arduous a task.

Regards,
Ian.

[MrQuade]

I always remove the hard drives before sending anything off for repair. Fortunately removing the Beyonwiz hard drives is not that arduous a task.

I know it doesn't bother most people but I absolutely hate opening the case and mucking around with hardware.

I think he's well aware that he can, and has done in the past. He just doesn't like doing it.

[IanSav]

Hi MrQuade,

I think he's well aware that he can, and has done in the past. He just doesn't like doing it.

Fair enough. Mrcell could also replicate the hard drive contents onto an external drive for safety.

Regards,
Ian.

[mrcell]

I'll update this thread to let you know how it goes.

I've had the U4 in for a week now with the only HDD being an external USB 3.0 bus powered 2TB drive. With the exception of an unrelated issue (which I've mentioned in another thread) everything is going ok. Timeshifting and recordings both seem fine. I've had one instance where I was recording on all 4 tuners (services from ABC, SBS, 9 and 10) and the recordings were ok except for some minor pixelation on one of them but this could have just been a random thing. It's pretty rare that I will be recording on 4 tuners simultaneously (as timer conflicts used to happen only about once a month on the T3) but I will keep an eye on this.

I would have preferred picking the drive like I did for the T3 (WD Purple) but I'm going to see how it goes as is. I can always buy a powered USB 3.0 caddy and use a 3.5" drive of my choice if I want to). Going by the size of the U4 I suspect it's a tight fit inside so I'm happy not to use an internal drive. I have pudgy fingers which is why I hated getting an internal drive in and out of the T3 so I don't think I'd like it any better with the U4.

[MrQuade]

It is a small case, but there is plenty of room for the 2.5" drive. The HDD mounting frame is one of the resort ones to remove too which is a bonus.

I'm glad the external arrangement is working out nicely though

[mrcell]

It is a small case, but there is plenty of room for the 2.5" drive. The HDD mounting frame is one of the resort ones to remove too which is a bonus.

Would you say it's easier than the T3? My specific issue with the T3 was that I couldn't access the front screws for the mounting frame if I attached the SATA and power connectors before screwing down the frame and plugging in the connectors after securing the frame was awkward for pudgy fingers and I was worried about damaging the front panel circuitry. (As it happens, my front panel did completely die some time ago but Warkus tells me this is a known issue with the T3 displays.)

[MrQuade]

Yes, the power and data connectors are far more accessible and I find the frame easier to remove than the T3's.

[mrcell]

Thanks Mr Quade, good to know.