Transfer speed from 20MBPS to 5MBPS

[H0R53]

I'm currently upgrading my storage and to avoid disaster I'm moving 252GB (174,429 items) worth of stuff to a RAID0 array before I wipe a drive for use in another array. It started at 10MBPS and shot up to 20MBPS within a minute or two but now it dropped to 5MBPS at 196GB left. Why is this happening?

[Arty]

2 minutes ago, H0R53 said:

I'm currently upgrading my storage and to avoid disaster I'm moving 252GB (174,429 items) worth of stuff to a RAID0 array before I wipe a drive for use in another array. It started at 10MBPS and shot up to 20MBPS within a minute or two but now it dropped to 5MBPS at 196GB left. Why is this happening?

Larger Files will have a higher transfer Speed than Smaller files, so when it transfers bigger files it does those quicker.

[flibberdipper]

File sizes, network use, fragmentation, potentially bad sectors... Take your pick, really.

[H0R53]

The drives are all new.

The 500GB the files are moving from is 10,000RPM with 64MB cache.

The two 160GB drives that the files are moving to are in RAID0 are both 7200RPM with 32MB cache.

 

Currently transferring Skyrim - Textures1.bsa (1,474,291KB) at 5.48MB/s

 

Doesn't make sense. Is the drive write cache full?

 

Edit: Okay, it's dropping fast, just watched it go from 5.45 to 5.35 in about 5 minutes.

[Sakkura]

HDDs will have random 4K IOPS on the order of 100-200, which translates to less than 1 MB/s. So if the average size gets very small, transfer speed gets very bad.

 

.bsa is an archive format, so maybe it's particularly susceptible to fragmentation if parts of it get updated.

[ARikozuM]

SATA can only handle a few files at a time in queue. NVMe speeds this up by allowing millions of files at a time.

[Electronics Wizardy]

6 minutes ago, H0R53 said:

The drives are all new.

The 500GB the files are moving from is 10,000RPM with 64MB cache.

The two 160GB drives that the files are moving to are in RAID0 are both 7200RPM with 32MB cache.

 

Currently transferring Skyrim - Textures1.bsa (1,474,291KB) at 5.48MB/s

 

Doesn't make sense. Is the drive write cache full?

 

Edit: Okay, it's dropping fast, just watched it go from 5.45 to 5.35 in about 5 minutes.

those are small files so it will be slow

 

Those drives are going to be slow as there old, esp the 160gb's. They haven't made 160gb drives for at least 6 years now.

[Sakkura]

8 minutes ago, ARikozuM said:

SATA can only handle a few files at a time in queue. NVMe speeds this up by allowing millions of files at a time.

HDDs cannot saturate SATA and is not held back by AHCI either.

 

By the way, NVMe doesn't replace SATA, it replaces AHCI. PCIe is what replaces SATA.

[ARikozuM]

Just now, Sakkura said:

HDDs cannot saturate SATA and is not held back by AHCI either.

 

By the way, NVMe doesn't replace SATA, it replaces AHCI. PCIe is what replaces SATA.

I'm not talking about the speed cap, but the queue depth. 

[H0R53]

I restarted my PC now it's like 35-ish now. Goes up and down a little.

 

Is there a Windows service that could be interfering? I have Superfetch disabled because it's useless.

 

Edit: dropping fast now, went from 35 to 29 in like 3 minutes while typing.

[H0R53]

Okay, after the first reboot i was able to pass the Skyrim file, and then after a second reboot everything seems fine. Fluctuates between 25.8 and 40 MB/s.