# Possible quiet upgrade drives



## romanpj (Dec 23, 2003)

As well as being a big fan of Tivo I'm also a bit of a 'Quiet PC' nerd  (amongst other things). So I came across this article:-

http://www.silentpcreview.com/article927-page1.html

and thought the Seagate especially would be an ideal Tivo drive. There's also a few pointers to other quiet drives. All we need to find now is a UK supplier. 

Paul


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## romanpj (Dec 23, 2003)

And another:-

http://www.eclipsecomputers.com/product.aspx?code=HDS-502HI

Anyone know if its any good?

Paul


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## mikerr (Jun 2, 2005)

Not tested them, but they look good.

Currrent ones we use are the Western Digital Green Power drives
also mentioned in the article above (though only 500GB and 1TB... not 2TB yet)


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## blindlemon (May 12, 2002)

I quite like the idea of the Samsung 5400rpm drives as their previous HA250JC was by far the best drive I've ever supplied for TiVo upgrades. Might just order a couple and see how they perform :up:

I wouldn't risk using a Seagate drive in a TiVo these days due to their firmware issues that aggravate the "helium sound" bug and prevent them being used in pairs. The newer WD IDE drives also have firmware problems that make them incompatible with TiVos too, although their Green Power SATA drives are currently my drives of choice for TiVo upgrades over 250gb.


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## ptruman (Jan 8, 2003)

What about SSDs?

Yes they are SATA, but an inline converter would mean you have total silence - but they ARE expensive...


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## mikerr (Jun 2, 2005)

SSDs would probably speed up tivo quite a lot due to the faster seek times, especially on non-cachecard tivos.

The constant writing to disk that tivo does would not be healthy for a SSD though.


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## Ian_m (Jan 9, 2001)

mikerr said:


> The constant writing to disk that tivo does would not be healthy for a SSD though.


Nope, completely wrong.

The TiVo write rate is so tiny compared to SSD's disks potential write speed that it would take the TiVo years to wear out an SSD.

For example.

TiVo write rate is say 10Mbits/sec (I know its less) -> 10/8Mbyte/sec = 1.25Mbyte/sec. (out of say an SSD max rate of 150Mbytes/sec ).

Thus an 80GB SSD would take 80,000,000,000/1,250,000 seconds to write once = 64,000 seconds = 17hours.

Assuming a SSD cell lifetime of 10,000 write (remember some are upto 100,000 or even 1,000,000 now), this would take 17hours x 10,000 = 170,000hours = 170,000/(24*365) years = 19years.:up:

So a TiVo wearing out an SSD is never going to happen.


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## ColinYounger (Aug 9, 2006)

Ian,

Nearly there!

TiVo's live buffer is a pre-set area of disk that is constantly written to as a 'stripe'. Therefore this area of the disk is written and re-written many times (once per your live buffer setting). Assuming 10,000 write and a 30 minute buffer, I make that to be 5,000 hours which is around 6 months.


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## mikerr (Jun 2, 2005)

What you describe happens on older SD and CF cards

SSD write levelling now occurs at the firmware level,
at least in modern HDD SSDs.

So the disk itself spreads the writes over the drive evenly.
In theory a new (over)write will go to a cell which has done less writing.
So Ian is right, but SSDs are too new for field data to prove the theory 

Live buffer:
Also the live buffer isn't set to a fixed area and rewritten anyway,
the procedure is something like this:

Record a chain of segments
continuously discard the oldest segment. 
So you always have the latest 30 minutes (e.g. 30 segments - you throw away the 31st segment every minute and create a new one in free space).

When you press record, tivo doesn't have to COPY any data.
It just marks those segments as now belonging to a particular program, and doesn't discard the oldest ones.

This is why on a tivo disk with bad sectors can be temporarily "fixed" by never deleting the stuttering program (the bad sectors are in use, so won't get reused).

If any of that makes sense


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## Ian_m (Jan 9, 2001)

ColinYounger said:


> TiVo's live buffer is a pre-set area of disk that is constantly written to as a 'stripe'. Therefore this area of the disk is written and re-written many times (once per your live buffer setting). Assuming 10,000 write and a 30 minute buffer, I make that to be 5,000 hours which is around 6 months.


Nope. SSD's don't work like this (which why people are having such issues with them).

If you continually write to the same sector on the disk for instance the SSD "wear levels" across all the Flash array in the device ie first sector write goes to location 0 in Flash array, 2nd write to first sector goes to location $200 (for instance), 3rd write to first sector to location $400 (for instance).

This way all the Flash gets written to evenly and theoretically all wears out at the same time.

The two slight flys in the ointment are
- the drive obviously maintains a translation table of whereabouts say sector 0 is located in the Flash array and this translation table get very "knotted" as time goes on and SSD drive writes can seriously slow down (I have seen 120MBytes/sec drive drop to 4MBytes/sec after a few days).
- Flash can only be erased in 512Kbyte blocks (depends on SSD, but this is typical). So to write say one sector, drive reads in 512kbyte block to RAM, modifies the sector you are writing, issues a block erase command (which takes a millisecond of two to complete) then writes the 512kbyte block back to Flash. This obviously seriously impacts writing speed.

As for TiVo at 1.25Mbytes/sec both the above problems would hardly be an issue.

One tech thing to look out for is Windows 7 support for SSD, supposedly supports write aggregation (block writes in 512kbyte chunks) and UMAP command to indicate an area of drive is no longer needed so the SSD can erase/"unknot" itself. Currently testing now, but nothing to report yet.


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## ColinYounger (Aug 9, 2006)

Ah. OK - my internal knowledgebase has been updated. I don't mind being wrong!


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## RichardJH (Oct 7, 2002)

ColinYounger said:


> I don't mind being wrong!


Then it is definitely NOT Pete under the bag


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## Ian_m (Jan 9, 2001)

ColinYounger said:


> Ah. OK - my internal knowledgebase has been updated. I don't mind being wrong!


Reason I know so much on SSD's as I have just spent the last couple of weeks evaluating SSD's for use in embedded computer systems, which in this limited application they are usually fine due to limited disk activity.

However in more powerful systems ie surveilance there are major performance issues with them due "write overloading" and severe speed degradation over time. I copied part of my desktop Vista system to 64GB Samsung SATA SSD to try, but kept on encountering severe annoying pauses occasionally, especially when exiting applications and saving. Also too small to be usefull on desktop. Anyway switched back to original high speed Seagate 500GB driver and whilst applications may not open so fast and PC makes a hum, don't suffer from annoyong pauses

The only SSD's I have seen immune to these problems are the Intel X25 series, but cost many times the amount of competitors.


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