# SSD on Tivo - Life Estimates



## telemark (Nov 12, 2013)

This came up in a HD thread and since running the numbers a few times, I thought I should post them to save them since this seems to come up from time to time.
http://www.tivocommunity.com/tivo-vb/showthread.php?p=10342547

*A few Tivo variables:
*Tivo Model
Tuner Counter
SD vs HD lineup
Bitrate of CableCo
Quality Setting
% of Keep Forever video

*SSD details:
*Storage Size
Flash type
Chip count
Chipset
Wear Level Algorithm
Warranty

*Potential advantages:
*Longevity
Power
Performance
Absolute Cost
Normalized Cost
Vibration / Temperature resistant

*Video Bit Charts:
*

```
Series 2 Best Quality compression:
(80 GB / 23 hours) * 1 year * 1 = 30.48 terabytes
(80 GB / 23 hours) * 1 year * 2 = 60.97 terabytes

Cable Co SD video:
OTA/ATSC SD video:

Cable Co HD video:
12 Mbps * 1 year * 1 =  47.33 terabytes
12 Mbps * 1 year * 2 =  94.67 terabytes (Premiere 2)
12 Mbps * 1 year * 4 = 189.34 terabytes (Roamio Basic)
12 Mbps * 1 year * 6 = 284.01 terabytes (Roamio Pro/+)

OTA/ATSC HD video:
19 Mbps * 1 year * 1 =  74.94 terabytes
19 Mbps * 1 year * 2 = 149.89 terabytes (Premiere 2)
19 Mbps * 1 year * 4 = 299.79 terabytes (Roamio Basic)
```
References:
http://techreport.com/review/26523/the-ssd-endurance-experiment-casualties-on-the-way-to-a-petabyte
http://en.wikipedia.org/wiki/Wear_leveling
http://thessdguy.com/2012/09/how-controllers-maximize-ssd-life-better-wear-leveling/


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## telemark (Nov 12, 2013)

In my Home, we use a Premiere 2 tuner on Cable.
Looking it up in the chart, this writes 95TB/year to the drive.

(If using Antenna, I would use 150TB/year instead. And if both, a weighted average depending on which I use more, or just the higher of the two.)

The Intel 335 Series (240GB) has been well tested on a PC. It lasted 750TB, which is 750TB/240GB = 3125x which we'll round to 3000x.

If I want the SSD to last 3 years, it would have to be:
((95TB / year) * 3 years) / 3000 = 95 gigabytes

If the SSD is less than 95GB it's expected to die from wear before the 3 year mark, and it should last longer if larger than 95GB.

Assumptions here are the SSD is using a wear leveling algorithm which still includes static data ( avoids Keep Forever video problems) and minimal write amplification ~1x. Other drive models might not have these properties.

Also note, it's proportional, so a 190GB Intel 335 SSD is expected to get 6 years on this setup.


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## BobCamp1 (May 15, 2002)

According to that first link, most SSD drives will handle 700 Tb of total data transfer before they go. So a Roamio Pro will last around 2.5 years on a typical cable system.

FIOS Roamio Pro users have a problem, since their encoding rates can achieve 15-18 Mbps for certain channels. So their hard drives might barely make it past the 2 year mark.

Also, I have heard that what helps the wear-leveling algorithm is to have around 10% of the SSD as unpartitioned space. I can't find the source of that though, so take it with a grain of salt. None of the Tivo tools I know will do that.

My Series 1 just died (I know, right?) and I also determined that an SSD drive could be used for it. But you'd have to get the right (expensive) PATA-SATA adapter, and I determined that it just wasn't worth it. But an S2 should have no problems with an SSD drive (or any pre-Roamio Tivo for that matter).


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## emerz (Aug 18, 2007)

BobCamp1 said:


> Also, I have heard that what helps the wear-leveling algorithm is to have around 10% of the SSD as unpartitioned space. I can't find the source of that though, so take it with a grain of salt. None of the Tivo tools I know will do that.


More information here:

http://www.samsung.com/global/business/semiconductor/minisite/SSD/global/html/about/whitepaper05.html


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## telemark (Nov 12, 2013)

BobCamp1 said:


> Also, I have heard that what helps the wear-leveling algorithm is to have around 10% of the SSD as unpartitioned space. I can't find the source of that though, so take it with a grain of salt. None of the Tivo tools I know will do that.


They might not do it by default but it shouldn't be too hard to make one do it.

Here's one non-Tivo but works for Tivo method using the HPA (Host Protection Area) and hdparm on Linux.
http://www.thomas-krenn.com/en/wiki/SSD_Over-provisioning_using_hdparm

Also it can be anywhere on the drive. So an Apple Free partition at the end is good enough, after the drive was wiped..


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