Question Slow Transfer Speeds

olds

Elite Member
Mar 3, 2000
50,056
716
126
I am transferring 100 GB from an 850 EVO SSD to a USB 3.0 thumb drive in a 3.0 port.

I started out at 25 MB/s and now 1 minute later am running between 4 and 15 MB/s.

Why so slow?

The EVO is capable of 520 and the USB drive 100 MB/s.

CPU: 8 core i7 @ 3.4 GHz
RAM 16 GB
GTX 1070
(Built it about 8 years ago, upgraded video card about 4 years ago)
TIA
 

Tech Junky

Diamond Member
Jan 27, 2022
3,412
1,145
106
System drive is out of cache or the USB is out of cache.

I have a cheap SanDisk that does 80MB/s that I picked up for $10 on Amazon but also have an extteme pro version that does 300MB/s+ and shows up as an SSD instead of a USB drive.


Up your game and get a better USB drive. IF you want to go even faster I have a TB4 that does 3GB/2.8GB I put together for ~$300 between the enclosure / drive / cable and a host card on the PC. Enclosure - $124 / Drive $100 / Cable $13 / Card $60
 

VirtualLarry

No Lifer
Aug 25, 2001
56,352
10,050
126
I am transferring 100 GB from an 850 EVO SSD to a USB 3.0 thumb drive in a 3.0 port.

I started out at 25 MB/s and now 1 minute later am running between 4 and 15 MB/s.

Why so slow?

The EVO is capable of 520 and the USB drive 100 MB/s.
Doubtful that the USB drive is rated at 100MB/sec write speeds. Most of the time, the advertised speeds turn out to be for reads.
 
  • Like
Reactions: Shmee

Tech Junky

Diamond Member
Jan 27, 2022
3,412
1,145
106
Doubtful that the USB drive is rated at 100MB/sec write speeds. Most of the time, the advertised speeds turn out to be for reads.
So true. This is why I test them for both. The extreme is nice for smaller data and the other I just use for booting iso images for recovering systems. The TB can be used for a bootable system though even windows will run from it without an internal drive hooked up.
 

tcsenter

Lifer
Sep 7, 2001
18,352
259
126
I have a couple performance USB 3.0 drives (major brands) that get HOT when writing large amounts of data. I would be surprised to learn if at least a few USB -> Flash controller chips did not have some kind of thermal management feature, and may throttle transfer/write speeds.
 
Last edited:

Shmee

Memory & Storage, Graphics Cards Mod Elite Member
Super Moderator
Sep 13, 2008
7,409
2,443
146
Also, depending on what you are transferring, the write speeds will be much slower to the USB drive. And this is true to any drive generally. Such as transferring many smaller files, such as documents and pics. If you are transferring larger files, like high quality videos or disc images, these generally go faster.