Originally Posted by cuda74360
I recently had alot of problems trying to put a 4K (Advanced Format, or AF) drive in my Tivo HD XL (TCD658000.) Please reference this thread:
I never could get it to work right, and have been running the reimaged stock drive without issues.
I'm now considering an upgrade, and was wondering about 4K compatibility in a Premiere. I know that the base Premiere comes with a non-AF drive. Even the new base Roamio comes with a non-AF drive.
Can anyone confirm that a 4K drive works correctly in a base Premiere, and that the partitions align? What about a base Roamio?
I remember reading your thread when considering whether to use an AF/4K 2TB drive to fix my broken S3 OLED or just sticking with the 512 1TB drive I had lying around.
I ended up first using the 512 1TB drive to repair the TiVo then getting a the AF/4K 2TB drive and upgrading using that.
From what I can guess, a lot of the AF/4K performance issues are now hidden by the firmware's tuned cache operation and larger caches.
I initially saw no performance issues with both tuners on SD channels and playing back an SD show.
Then I switched to both tuners on HD channels and playing back an HD show and also MRV of an HD show to another S3. Still no performance issues.
Then I did a manually connect to mothership and still no issues with it running in the background.
Finally I did start seeing performance issues. It coincided with Guide Cache going from "Idle, since..." to "Running, since...".
If I skipped back/forward and ff/rew slowly it was still ok, but if I did things too rapidly and throwing in the Now Playing List in between I could get things to kind of hang and be unresponsive, but it eventually came back. Now Playing List would take longer to display the list of shows. This degraded performance would persist for a few hours, but eventually it became normal again. That was around the time the guide cache went back to "Idle, since..."
Right now everything is back to normal and working just as good as my original drive.
I timed the connect to mothership between the S3 OLED using the Seagate 750GB DB35 against the S3 OLED using the 2TB WD20EURS and the WD20 is just as fast.
The only thing I notice is the initial bringing up of Now Playing List is slower than on my other S3 (which is still using Seagate 750GB DB35), but after that it starts becoming normal again. I believe what is happening is the caching algorithms start guessing what to preload after the initial load and it doesn't go back to disk as often and thus are less affected by the two HD streams writing in the background.
One thing to realize is that even if you are misaligned, it won't really affect sequential write performance (which is what TiVo is most often doing). It mainly affects random write performance, which I am guessing is what is more likely happening with the guide cache indexing while the two streams write in the background sequentially.
Also a lot of the misalignment can be hidden by advanced predictive cache loading of blocks in the drive firmware. So these newer drives with 64MB cache and newest firmware can probably do a pretty good job of hiding the performance issues when used in TiVo. I know the Seagates have there SmartAlign feature implemented in the cache's predictive loading algorithms. I suspect WD has something similar in their latest firmwares but doesn't advertise.
Anyway, the drive is functioning very well right now. Slight delay on the initial NPL but I can live with that. I suspect if I leave the TiVo disconnected for 2 weeks and have to download 13 days of guide data and index, I will see performance issues again, but I am not going to bother testing. My conclusion is you can get to the point where the performance degradation can be seen, but for normal operations everything should be fine.
This is with
- Model Number: WDC WD20EURS-73TLHY0
- Firmware Number: 80.00A80
- Capacity: 2000.40 GB
- Product of Malaysia
- DATE: 30 JUL 2013
Also for future reference, my MFS 1 and MFS 2 media partitions are 4K aligned. My linux swap, /var, and MFS 3 media partition are not 4K-aligned. My MFS 1/2 are full (the TiVo was full before I upgraded the drive) and the beginning of MFS 3 is full also, so I'm definitely writing in the non-aligned section)