Is 64GB of HDD cache enough to read UHD videos?

LMiller7 said:

Applications and the OS itself have no access to the HD cache. This is used internally by the drive itself. The cache that is relevant to video playback is the file cache maintained by the OS. With 8 GB RAM this will typically be several hundred MB but can be much larger if there is a need. Task Manager will tell you nothing about this. The "Cached" value shown in Task Manager is something else.

I would expect a larger HD cache to have little relevance to your purposes.

Really appreciate the insights. I didn't know HD cache was only internally used by the HDD itself.
I do have 8GB of ram and currently have 0 issue playback 4k video files. Based on your explanation I can assume that swapping to an 5400RPM 64MB HD will not affect the my playback

Megahertz said:

Are you talking about HDD for desktop or laptop?
5400RPM HDD are normally for laptops (2.5") as they have lower gyroscopic effect.
WD blue isn't first grade line. I wold look for WD black or Gold (5 years warranty)

Sorry I didn't precise. HDD for desktop 3.5".
What sold me on the 5400rpm class is the fact that due to the disk spinning slower, it generates less vibration and is quieter. Apparently the fact that it's spinning slower also increase the reliability of the HDD.

I know the blue line is entry level but I don't really need anything fancy or high perf as I will only be using it for storage and video playback.

NavyLCDR said:

Hard drive cache size is not going to matter for reading video files.

Thanks for confirming.

Compumind said:

@Arese -

Why not a 2 TB SSD?

For HDD's - when you read large continuous files (like movies) then you are limited to the speed of the data transfer. Cache will not boost this.

I wouldn't even use 2% of an SSD data transfer speed.
I monitored my HDD transfer speed when playing an 80GB video file with 90MB/s video bitrate and it's only reading at an average of 9MB/s
A 5400RPM HD with read speed around 100MB/s will be more than enough.

Thanks for confirming that for reading large continuous files only the speed of data transfer matters. That's all I needed to confirm.

Berton said:

Your Subject says 64GB but the question mentions 64MB, can it be assumed the 64MB is intended?

One thing additional RAM may help is in streaming videos, I need to upgrade her Toshiba from 4GB RAM to 8GB or maybe its maximum of 16GB for her viewing of live streaming. If it were on-drive video playing all the way through then replaying usually smooths things out.

Thanks for pointing that out I've fixed up the title. I meant 64MB cache.
I can confirm additional RAM will help with reading high quality 4k files.
I previously had some intermittent frame drops when playing large 4k video files (Well it turns out a memtest revealed that my memory sticks were generating errors)
I swapped my faulty RAMs and now I can playback 3840x2160 video files with bitrate upwards 90MB/s without 1 frame drop.

Thanks everyone for your input, they were all really insightful, this is such a great community and I appreciate everyone taking the time to answer.

I'm going to go with an 5400RPM 64MB HD as i'm now convinced that upgrading to 128MB cache will make no difference

@Arese -

Might I suggest a 7200 RPM HDD? There are some great HDD's with a lower dB level.
I'm not a fan of 5400's. Price difference is very small.

There are also several media players with their own cache (sometimes adjustable)
Some can cache a whole video and play it back if it were in ram.

NavyLCDR said:

Another question, though..... why get a 7200 RPM HDD if you don't really need it? Even if it is just $20 more, it's still, well....$20 back in your pocket. A 7200 RPM drive will save the movies written to it faster, sure. But playing the movies is completely different. You only need to feed the media player at the rate it can play the movie. Any somewhat modern HDD can very easily feed 1 UHD video stream.

It's subjective.

I know what the OP wants to do but I always think of the future. You can use a 5400, 7200 or an SSD depending on the price.
For a application such as this, the costs of a 7200 versus a 5400 are so close, if not exact. Depends on the vendor and stock.

There is no right or wrong here. Let the OP buy a higher capacity drive and a 7200 rotational speed, That should be just fine.

You can never store enough, anyway.

FWIW.

@Arese -

So what did you decide to finalize on?
Just curious.

@Arese -

I'm glad that you bought what you wanted. At least you had some good opinions before you did so!
Now, enjoy the HTPC!

Cheers!