Solved Cannot access USB hard disks, only USB flash drives

gunrunnerjohn · Sep 2, 2025

spapakons said:
I would swear that my USB flash drive works faster when connected to the powered USB 3.0 hub. Probably my older PCIe x1 port cannot make the USB 3.0 PCIe card work at full speed and the external power helps improve performance. 90-100MB (720-800Mbps) write speed for a mechanical USB hard disk is not bad.

A USB 3.0 port is incapable of doing 720-800MB/sec, it's absolute theoretical maximum is 5Gbps or 625 MBs. Also, the fastest HDD drives transfer do 130MB/sec to maybe 150MB/sec, so that's even farther out.

Marie SWE · Sep 2, 2025

gunrunnerjohn said:
A USB 3.0 port is incapable of doing 720-800MB/sec, it's absolute theoretical maximum is 5Gbps or 625 MBs. Also, the fastest HDD drives transfer do 130MB/sec to maybe 150MB/sec, so that's even farther out.

you read wrong from the post it says 720-800Mbps its bits not bytes

gunrunnerjohn · Sep 3, 2025

Marie SWE said:
you read wrong from the post it says 720-800Mbps its bits not bytes

OK, that's kinda' slow.

You're down to not much more than USB 2.0 speeds at that rate. Of course, now we're looking the PCIe x1 expansion slot, so that will limit speeds further, the PCIe 1.x x1 slot offers 250MB/sec max and likely much less at the USB end I suspect.

Marie SWE · Sep 3, 2025

gunrunnerjohn said:
OK, that's kinda' slow. You're down to not much more than USB 2.0 speeds at that rate. Of course, now we're looking the PCIe x1 expansion slot, so that will limit speeds further, the PCIe 1.x x1 slot offers 250MB/sec max and likely much less at the USB end I suspect.

if its an external HDD then its good speed.

spapakons · Sep 3, 2025

It is an external mechanical hard disk. Not SSD, so the speeds are OK.

gunrunnerjohn · Sep 3, 2025

spapakons said:
It is an external mechanical hard disk. Not SSD, so the speeds are OK.

The USB 3.0 port has a 900ma limit at 5V, that's 4.5 watts. That probably isn't enough for some HDD models, but it should support any SSD.

What do you actually see running something like CrystalDiskMark on them? I admit, the HDD isn't a speed champ on any interface.

OTOH, an SSD on a USB 3.0 port should be a lot better.

spapakons · Sep 3, 2025

This is my Windows SSD:

WD Blue 1TB SATA III SSD Crystal Disk Mark.webp

It might be better if I had full SATA III speed, but my combo USB 3.0 and SATA III PCIe x1 version 4.0 card works on a PCIe 1x version 3.0 slot.

This is one of my USB 3.0 USB flash drives connected on the powered USB 3.0 hub:

Sandisk 16GB USB 3.0 flash drive Crystal Disk Mark.webp

No bad performance, without the powered USB 3.0 hub I had lower figures. Of course these figures are for transferring large files without the CPU supervising all the time (aka DMA, Direct Memory Access). If I transfer many small files (such as text of photos) the CPU is notified after each start/end of transfer and this impacts the speed.

gunrunnerjohn · Sep 3, 2025

I prefer the speed of my PNY PRO Elite FLASH drive on a USB 3.0 port.

Scannerman · Sep 3, 2025

gunrunnerjohn said:
I prefer the speed of my PNY PRO Elite FLASH drive on a USB 3.0 port.

View attachment 144286

Don't you mean USB 3.1? The nomenclature got changed, right? :zany:

spapakons · Sep 3, 2025

gunrunnerjohn said:
I prefer the speed of my PNY PRO Elite FLASH drive on a USB 3.0 port.

View attachment 144286

Surely it costed much more than a typical 256GB USB 3.0 flash drive. Until recently I only had USB 2.0 ports in my PC (transfer speed 20MB/sec max), so anything higher is welcome. I don't need yet something that fast and that expensive.

gunrunnerjohn · Sep 3, 2025

Scannerman said:
Don't you mean USB 3.1? The nomenclature got changed, right?

USB 3.2 Gen 1 has a maximum theoretical data transfer speed of 5 gigabits per second (Gbps), or 5,000 megabits per second (Mbps). This standard was previously known by several names, including USB 3.0 and USB 3.1 Gen 1. I just use USB 3.0 to describe any of these ports with a USB-A connection as the characteristics are the same.

USB 3.2 and 3.1 Explained: What's Gen 1, Gen 2 and Gen 2x2?

As you can see, the USB types and generations area a mish-mash of specifications that are obviously meant to confuse mere mortals.

gunrunnerjohn · Sep 3, 2025

spapakons said:
Surely it costed much more than a typical 256GB USB 3.0 flash drive. Until recently I only had USB 2.0 ports in my PC (transfer speed 20MB/sec max), so anything higher is welcome. I don't need yet something that fast and that expensive.

My 256GB PNY PRO Elite FLASH drive is $28 on Amazon, not actually that price prohibitive. It's actually not that much more than a much slower 256GB FLASH drive.

spapakons · Sep 3, 2025

After copying some files from work old Windows 7 computers (transfer speed 7-10MB/sec) anything higher than 30MB/sec feels like blazing fast.

gunrunnerjohn · Sep 3, 2025

spapakons said:
After copying some files from work old Windows 7 computers (transfer speed 7-10MB/sec) anything higher than 30MB/sec feels like blazing fast.

That feeling fades when you copy stuff to the FLASH drive at 400MB/sec.

spapakons · Sep 3, 2025

For comparison my first 40MB hard disk was just a little faster than a floppy disk drive. I thought that was because it was on a slow 8088 computer. It was connected to a full size (from back to front) 8-bit card with the HDD controller, as the 8088 motherboard didn't have any hard disk controller. When I wanted to backup some files and moved the card with the HDD controller and the hard disk in my much faster Pentium I PC, it was still slow, almost comparable to a floppy disk! Any contemporary IDE hard disk was like a fast SSD compared to the old disk!

Scannerman · Sep 3, 2025

gunrunnerjohn said:
USB 3.2 Gen 1 has a maximum theoretical data transfer speed of 5 gigabits per second (Gbps), or 5,000 megabits per second (Mbps). This standard was previously known by several names, including USB 3.0 and USB 3.1 Gen 1. I just use USB 3.0 to describe any of these ports with a USB-A connection as the characteristics are the same.

USB 3.2 and 3.1 Explained: What's Gen 1, Gen 2 and Gen 2x2?

As you can see, the USB types and generations area a mish-mash of specifications that are obviously meant to confuse mere mortals.

I went ROGUE and simplified it further: I call USB in the 3 class three even if it's E or C. It makes little difference to me you see, as all of it is really three when I speak about it generally. Admittedly, there are many types of USB three and some (I think) that should not be. To confuse the matter even more trouble brews with USB4, but I think it's time to shut the door before I become a terrible bore.

gunrunnerjohn · Sep 3, 2025

Scannerman said:
I went ROGUE and simplified it further: I call USB in the 3 class three even if it's E or C. It makes little difference to me you see, as all of it is really three when I speak about it generally. Admittedly, there are many types of USB three and some (I think) that should not be. To confuse the matter even more trouble brews with USB4, but I think it's time to shut the door before I become a terrible bore.

We just have to face it, they really screwed up when they started naming the different "types" of USB.

Scannerman · Sep 3, 2025

gunrunnerjohn said:
We just have to face it, they really screwed up when they started naming the different "types" of USB.

Indubitably. The re-naming scheme didn't help much either. It would seem they're trying to continue the tradition with USB4 and Thunderbolt4 too. Insane!

gunrunnerjohn · Sep 3, 2025

Scannerman said:
Indubitably. The re-naming scheme didn't help much either. It would seem they're trying to continue the tradition with USB4 and Thunderbolt4 too. Insane!

Yep, it hasn't sunk in that they screwed up with the previous naming, so they're just continuing the confusion!

spapakons · Sep 4, 2025

Any 3 is faster than USB 2.0, so it is welcome. Are there USB 4.0 PCIe cards? I am in no hurry to replace my recently bought combo USB 3.0 and SATA III PCIe card, just curious.

Solved Cannot access USB hard disks, only USB flash drives

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USB 3.2 and 3.1 Explained: What's Gen 1, Gen 2 and Gen 2x2?​

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USB 3.2 and 3.1 Explained: What's Gen 1, Gen 2 and Gen 2x2?​

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