Does MakeMKV lock or limit drive access while it's in use?
Does MakeMKV lock or limit drive access while it's in use?
I have two raid 50 virtual disks composed of eight 3TB 7200 RPM drives each. I can usually transfer large files between the two virtual drives at around 700MBps-1GBps... However, whenever I have MakeMKV going, the write speed of MakeMKV's destination drive gets a speed limit of about 50-80MBps write speed. I can stop the rip process and suddenly my transfers return to normal speed - start the rip process again and the write speeds diminish again. Any reason why this happens? I have two bdroms and it happens with both of them, one SATA and the other USB3. Just find it weird... wondering if I have something setup incorrectly?
Re: Does MakeMKV lock or limit drive access while it's in use?
It will depend upon how much buffering your drive system does. Remember that raw throughput does not take into account directory updates, and if you are not writing a contiguous block of data, the array has to update the file system's directory. Even with buffered writes, the operating system is going to limit how long it holds directory information in the cache.
MakeMKV is doing writes as fast as it can read from the optical media. If you're also doing writes from another task (or multiple other tasks), the array is also moving the heads around to obey all the "masters"; Seek time isn't write time.
MakeMKV is doing writes as fast as it can read from the optical media. If you're also doing writes from another task (or multiple other tasks), the array is also moving the heads around to obey all the "masters"; Seek time isn't write time.
MakeMKV Frequently Asked Questions
How to aid in finding the answer to your problem: Activating Debug Logging
How to aid in finding the answer to your problem: Activating Debug Logging
Re: Does MakeMKV lock or limit drive access while it's in use?
Well the write speeds I'm talking about are constant - as in moving a 60GB UHD MKV file between virtual drives. If it's a 500MB file, it'll report some silly cache number like 7.5GBps or something, but huge files level out to somewhere between 700 and 1000 MBps. MakeMKV says it's copying at around 30MBps at most, and according to windows performance monitor, nothing else is happening other than MakeMKV "in progress". Just find it weird that it cripples the system so badly.
I just tested it on my NVMe drive too - same thing happens there as well. When MakeMKV runs, it throttles the destination drives bandwidth.
I just tested it on my NVMe drive too - same thing happens there as well. When MakeMKV runs, it throttles the destination drives bandwidth.
Re: Does MakeMKV lock or limit drive access while it's in use?
So, if you start multiple copy operations between the drives, the aggregate speed never drops below 700 MB/s? That's highly unusual.
I see degradation in overall copy speed even with a dedicated processor handling the drives, when multiple streams are involved. If it were an SSD array, the affect of "seeks" is near zero, but moving heads on physical arrays is significant, unless operations are heavily buffered to minimize the number of times the heads have to move. And even with buffering, when you hit the limit of the buffer, the input side is slowed to a crawl while the buffer is written.
I'm assuming here that your RAID is based on a dedicated controller, so it isn't a CPU loading situation. Even then, a lot depends on your safety settings, such as how long write cache data is allowed to stay in the cache. A big cache is useless if power gets interrupted.
I see degradation in overall copy speed even with a dedicated processor handling the drives, when multiple streams are involved. If it were an SSD array, the affect of "seeks" is near zero, but moving heads on physical arrays is significant, unless operations are heavily buffered to minimize the number of times the heads have to move. And even with buffering, when you hit the limit of the buffer, the input side is slowed to a crawl while the buffer is written.
I'm assuming here that your RAID is based on a dedicated controller, so it isn't a CPU loading situation. Even then, a lot depends on your safety settings, such as how long write cache data is allowed to stay in the cache. A big cache is useless if power gets interrupted.
MakeMKV Frequently Asked Questions
How to aid in finding the answer to your problem: Activating Debug Logging
How to aid in finding the answer to your problem: Activating Debug Logging
Re: Does MakeMKV lock or limit drive access while it's in use?
I just tried copying one mkv from D to E and another from E to D simultaneously. They seem to fight about who gets to go faster, but neither drops below 150MBps (except directly at the start of the bidirectional start, that seems to lock progress for a few seconds).
I can understand writing some data to the hard disk is going to block some iops from another copy of data happening, but makemkv only reports 40MBps tops typically, so I'm not sure why the rest of the destination drives iops collapse so hard. If I copy some mkv's from a usb drive (at 80-100MBps) to the destination drive, I'm still able to copy other stuff to it or from it and get good speeds. But MakeMKV appears to capitalize on the iops or bandwidth somehow. That's all I'm saying...
I can understand writing some data to the hard disk is going to block some iops from another copy of data happening, but makemkv only reports 40MBps tops typically, so I'm not sure why the rest of the destination drives iops collapse so hard. If I copy some mkv's from a usb drive (at 80-100MBps) to the destination drive, I'm still able to copy other stuff to it or from it and get good speeds. But MakeMKV appears to capitalize on the iops or bandwidth somehow. That's all I'm saying...