SD Card reader speed

[skanter]

My Dell XPS 8940 hs a card reader, but slow at 25 MB/sec. So I bought this reader:


uni SD Card Reader, High-Speed USB 3.0 to Micro SD Card Adapter, Aluminum Computer Memory Card Reader Dual Slots, for SD/SDXC/SDHC/MMC/Micro SDXC/TF/Micro SDHC | Laptop, PC, and More https://a.co/d/dTVLFfW

My Dell XPS 8940 has 3 USB 3.1 gen 1 ports on front. I am using a Sandisk extreme 200MB card, UHS-1, but only getting 60-70 MB/sec transfer speed. Shouldn't it be faster? Where is slowdown? Thanks in advance…

 

[Dick Dastardly]

My Dell XPS 8940 hs a card reader, but slow at 25 MB/sec. So I bought this reader:

My Dell XPS 8940 has 3 USB 3.1 gen 1 ports on front. I am using a Sandisk extreme 200MB card, UHS-1, but only getting 60-70 MB/sec transfer speed. Shouldn't it be faster? Where is slowdown? Thanks in advance…

I looked at the Amazon picture, it clearly states 104 mb read/write speeds for that model. In real life, this translates to the numbers you are currently getting.

Obviously, the card reader is a limitation, but 60-70 mb/s is a very respectable speed. I mean, have you even obtained a faster transfer rate between a computer and a card using a external USB reader? Because I haven't.

I have also looked up your memory card, the internet says that the bus limit for UHS-1 is around 104 mbs, matching the info on the reader and the real life speeds you are currently getting. So there's nothing unusual here.

If you bought the "200 mbs" memory card and expected that to translate into 200 mb/s transfer speed, that's not what the number means, it does not represent the actual transfer speed possible and yes, it is a bit misleading for them to advertise them as such.

But again, 70 mb/s is a very respectable transfer speed, since the bus limitation is 104 mb/s. You can probably slightly increase that number with a pro card reader, but I wouldn't bother.

 

[kelpdiver]

from the Amazon vendor description

"Tip - 1 !! This USB SD card adapter reads UHS-II memory cards at UHS-I speed."

UHS-I speed has a theoretical max of 104MB/s, so 72 doesn't seem offbase.

For $11, not a bad deal on a card reader, but if you want faster, probably need to speed a tad more.

 

[skanter]

My Dell XPS 8940 hs a card reader, but slow at 25 MB/sec. So I bought this reader:

My Dell XPS 8940 has 3 USB 3.1 gen 1 ports on front. I am using a Sandisk extreme 200MB card, UHS-1, but only getting 60-70 MB/sec transfer speed. Shouldn't it be faster? Where is slowdown? Thanks in advance…

I looked at the Amazon picture, it clearly states 104 mb read/write speeds for that model. In real life, this translates to the numbers you are currently getting.

Obviously, the card reader is a limitation, but 60-70 mb/s is a very respectable speed. I mean, have you even obtained a faster transfer rate between a computer and a card using a external USB reader? Because I haven't.

I have also looked up your memory card, the internet says that the bus limit for UHS-1 is around 104 mbs, matching the info on the reader and the real life speeds you are currently getting. So there's nothing unusual here.

If you bought the "200 mbs" memory card and expected that to translate into 200 mb/s transfer speed, that's not what the number means, it does not represent the actual transfer speed possible and yes, it is a bit misleading for them to advertise them as such.

But again, 70 mb/s is a very respectable transfer speed, since the bus limitation is 104 mb/s. You can probably slightly increase that number with a pro card reader, but I wouldn't bother.

Thanks for the response. Do you think a UHS-2 card and reader would achieve 3X the speed, or significantly more? I can live with 60-90 MB/sec now, however - especially compared to 24MB/sec with built-in SD reader.

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[skanter]

from the Amazon vendor description

"Tip - 1 !! This USB SD card adapter reads UHS-II memory cards at UHS-I speed."

UHS-I speed has a theoretical max of 104MB/s, so 72 doesn't seem offbase.

For $11, not a bad deal on a card reader, but if you want faster, probably need to speed a tad more.

I think I’d need a UHS-2 card and reader, but how much increased speed?

 

[Carey Brown]

My Dell XPS 8940 hs a card reader, but slow at 25 MB/sec. So I bought this reader:

uni SD Card Reader, High-Speed USB 3.0 to Micro SD Card Adapter, Aluminum Computer Memory Card Reader Dual Slots, for SD/SDXC/SDHC/MMC/Micro SDXC/TF/Micro SDHC | Laptop, PC, and More https://a.co/d/dTVLFfW

My Dell XPS 8940 has 3 USB 3.1 gen 1 ports on front. I am using a Sandisk extreme 200MB card, UHS-1, but only getting 60-70 MB/sec transfer speed. Shouldn't it be faster? Where is slowdown? Thanks in advance…

A UHS-1 card reader's max transfer speed is up to 104 MB/s, UHS-2 speed is up to 312 MB/s. Your USB 3.1 Gen 1 port max is up to about 500 MB/s (allowing for some protocol overhead). So, if you want faster transfers then upgrading to a UHS-2 reader would be the thing to do. At that point you'll have to pay attention to the cable you are using because that would be the next bottleneck culprit.

 

[Carey Brown]

My Dell XPS 8940 hs a card reader, but slow at 25 MB/sec. So I bought this reader:

uni SD Card Reader, High-Speed USB 3.0 to Micro SD Card Adapter, Aluminum Computer Memory Card Reader Dual Slots, for SD/SDXC/SDHC/MMC/Micro SDXC/TF/Micro SDHC | Laptop, PC, and More https://a.co/d/dTVLFfW

My Dell XPS 8940 has 3 USB 3.1 gen 1 ports on front. I am using a Sandisk extreme 200MB card, UHS-1, but only getting 60-70 MB/sec transfer speed. Shouldn't it be faster? Where is slowdown? Thanks in advance…

A UHS-1 card reader's max transfer speed is up to 104 MB/s, UHS-2 speed is up to 312 MB/s. Your USB 3.1 Gen 1 port max is up to about 500 MB/s (allowing for some protocol overhead). So, if you want faster transfers then upgrading to a UHS-2 reader would be the thing to do. At that point you'll have to pay attention to the cable you are using because that would be the next bottleneck culprit.

Ah, I believe the card you are using is UHS-1 so an upgrade of the reader won't work unless you also upgrade your card to one that supports UHS-2.

 

[skanter]

My Dell XPS 8940 hs a card reader, but slow at 25 MB/sec. So I bought this reader:

uni SD Card Reader, High-Speed USB 3.0 to Micro SD Card Adapter, Aluminum Computer Memory Card Reader Dual Slots, for SD/SDXC/SDHC/MMC/Micro SDXC/TF/Micro SDHC | Laptop, PC, and More https://a.co/d/dTVLFfW

My Dell XPS 8940 has 3 USB 3.1 gen 1 ports on front. I am using a Sandisk extreme 200MB card, UHS-1, but only getting 60-70 MB/sec transfer speed. Shouldn't it be faster? Where is slowdown? Thanks in advance…

A UHS-1 card reader's max transfer speed is up to 104 MB/s, UHS-2 speed is up to 312 MB/s. Your USB 3.1 Gen 1 port max is up to about 500 MB/s (allowing for some protocol overhead). So, if you want faster transfers then upgrading to a UHS-2 reader would be the thing to do. At that point you'll have to pay attention to the cable you are using because that would be the next bottleneck culprit.

Ah, I believe the card you are using is UHS-1 so an upgrade of the reader won't work unless you also upgrade your card to one that supports UHS-2.

So, if I got a UHS-2 card and UHS-2 reader, how fast might transfers be?

 

[skanter]

My Dell XPS 8940 hs a card reader, but slow at 25 MB/sec. So I bought this reader:

uni SD Card Reader, High-Speed USB 3.0 to Micro SD Card Adapter, Aluminum Computer Memory Card Reader Dual Slots, for SD/SDXC/SDHC/MMC/Micro SDXC/TF/Micro SDHC | Laptop, PC, and More https://a.co/d/dTVLFfW

My Dell XPS 8940 has 3 USB 3.1 gen 1 ports on front. I am using a Sandisk extreme 200MB card, UHS-1, but only getting 60-70 MB/sec transfer speed. Shouldn't it be faster? Where is slowdown? Thanks in advance…

A UHS-1 card reader's max transfer speed is up to 104 MB/s, UHS-2 speed is up to 312 MB/s. Your USB 3.1 Gen 1 port max is up to about 500 MB/s (allowing for some protocol overhead). So, if you want faster transfers then upgrading to a UHS-2 reader would be the thing to do. At that point you'll have to pay attention to the cable you are using because that would be the next bottleneck culprit.

Cable is attached (part of) card reader.

 

[BobKnDP]

My Dell XPS 8940 hs a card reader, but slow at 25 MB/sec. So I bought this reader:

uni SD Card Reader, High-Speed USB 3.0 to Micro SD Card Adapter, Aluminum Computer Memory Card Reader Dual Slots, for SD/SDXC/SDHC/MMC/Micro SDXC/TF/Micro SDHC | Laptop, PC, and More https://a.co/d/dTVLFfW

My Dell XPS 8940 has 3 USB 3.1 gen 1 ports on front. I am using a Sandisk extreme 200MB card, UHS-1, but only getting 60-70 MB/sec transfer speed. Shouldn't it be faster? Where is slowdown? Thanks in advance…

A review of a 512GB model:

SanDisk Extreme PRO SD Card Review - StorageReview.com

Apparently, it's possible to achieve close to a 200MB/s sequential read speed, using a SanDisk reader . It's a $55 device.

If your SD card is smaller, its read/write speeds may be less. Or not.

Whether a UHS-2 reader could exploit the nonstandard (UHS-1) speed of the SanDisk card, I can't guess.

(I mainly use CF Express cards, and a reader that connects to a USB 3.2 Gen2 Type C port.)

 

[skanter]

My Dell XPS 8940 hs a card reader, but slow at 25 MB/sec. So I bought this reader:

uni SD Card Reader, High-Speed USB 3.0 to Micro SD Card Adapter, Aluminum Computer Memory Card Reader Dual Slots, for SD/SDXC/SDHC/MMC/Micro SDXC/TF/Micro SDHC | Laptop, PC, and More https://a.co/d/dTVLFfW

My Dell XPS 8940 has 3 USB 3.1 gen 1 ports on front. I am using a Sandisk extreme 200MB card, UHS-1, but only getting 60-70 MB/sec transfer speed. Shouldn't it be faster? Where is slowdown? Thanks in advance…

A review of a 512GB model:

SanDisk Extreme PRO SD Card Review - StorageReview.com

Apparently, it's possible to achieve close to a 200MB/s sequential read speed, using a SanDisk reader . It's a $55 device.

If your SD card is smaller, its read/write speeds may be less. Or not.

Whether a UHS-2 reader could exploit the nonstandard (UHS-1) speed of the SanDisk card, I can't guess.

(I mainly use CF Express cards, and a reader that connects to a USB 3.2 Gen2 Type C port.)

My research indicates that a UHS-2 reader would not increase speed of a UHS-1card. I would need both card and reader UHS-2. I think I will settle for the 3X speed over the internal SD reader, and stick with my 11 dollar investment.

 

[kelpdiver]

a reliable 70/min still means 15 seconds per gigabyte. On a twice a year basis, I might come back with 200gb in data across CFE, microsd, and sdhc. It can be slow, but it runs in the background.

 

[skanter]

a reliable 70/min still means 15 seconds per gigabyte. On a twice a year basis, I might come back with 200gb in data across CFE, microsd, and sdhc. It can be slow, but it runs in the background.

Not sure what you mean.

I regularly have cards with over 1000 26MB files that i will process in LR. With the internal SD reader I went away and did something else while transferring, 15or 20 minutes. Hoping to get started sooner with PP.

 

[Carey Brown]

My Dell XPS 8940 hs a card reader, but slow at 25 MB/sec. So I bought this reader:

uni SD Card Reader, High-Speed USB 3.0 to Micro SD Card Adapter, Aluminum Computer Memory Card Reader Dual Slots, for SD/SDXC/SDHC/MMC/Micro SDXC/TF/Micro SDHC | Laptop, PC, and More https://a.co/d/dTVLFfW

My Dell XPS 8940 has 3 USB 3.1 gen 1 ports on front. I am using a Sandisk extreme 200MB card, UHS-1, but only getting 60-70 MB/sec transfer speed. Shouldn't it be faster? Where is slowdown? Thanks in advance…

A UHS-1 card reader's max transfer speed is up to 104 MB/s, UHS-2 speed is up to 312 MB/s. Your USB 3.1 Gen 1 port max is up to about 500 MB/s (allowing for some protocol overhead). So, if you want faster transfers then upgrading to a UHS-2 reader would be the thing to do. At that point you'll have to pay attention to the cable you are using because that would be the next bottleneck culprit.

Ah, I believe the card you are using is UHS-1 so an upgrade of the reader won't work unless you also upgrade your card to one that supports UHS-2.

So, if I got a UHS-2 card and UHS-2 reader, how fast might transfers be?

Based on the numbers I'm betting at least 3x of what you're getting with UHS-1.

--
Photos at http://inasphere.com

 

[skanter]

My Dell XPS 8940 hs a card reader, but slow at 25 MB/sec. So I bought this reader:

uni SD Card Reader, High-Speed USB 3.0 to Micro SD Card Adapter, Aluminum Computer Memory Card Reader Dual Slots, for SD/SDXC/SDHC/MMC/Micro SDXC/TF/Micro SDHC | Laptop, PC, and More https://a.co/d/dTVLFfW

My Dell XPS 8940 has 3 USB 3.1 gen 1 ports on front. I am using a Sandisk extreme 200MB card, UHS-1, but only getting 60-70 MB/sec transfer speed. Shouldn't it be faster? Where is slowdown? Thanks in advance…

A UHS-1 card reader's max transfer speed is up to 104 MB/s, UHS-2 speed is up to 312 MB/s. Your USB 3.1 Gen 1 port max is up to about 500 MB/s (allowing for some protocol overhead). So, if you want faster transfers then upgrading to a UHS-2 reader would be the thing to do. At that point you'll have to pay attention to the cable you are using because that would be the next bottleneck culprit.

Ah, I believe the card you are using is UHS-1 so an upgrade of the reader won't work unless you also upgrade your card to one that supports UHS-2.

So, if I got a UHS-2 card and UHS-2 reader, how fast might transfers be?

Based on the numbers I'm betting at least 3x of what you're getting with UHS-1.

Would a UHS-II card like this offer any speed advantages while capturing in camera over UHS-I card? 64 GB is only $5 cheaper (faster, slower, or same)?

SanDisk 128GB Extreme PRO SDXC UHS-II Memory Card - C10, U3, V60, 6K, 4K UHD, SD Card - SDSDXEP-128G-GN4IN https://a.co/d/17E60rE

It would cost about 50 bucks to upgrade card and reader.

--
Sam K., NYC
“I’m halfway between tightrope walker and pickpocket.” HCB
—
__
Smugmug Galleries:
http://skanter.smugmug.com
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https://www.instagram.com/sam.kanter/

 

[number_5]

Your a6400 can't fully utilize UHS-II card.

I use UHS-II V90 SD, and the practical transfer rate to a PC is about 120-180MB/s using a dual CFExpress A & UHS-II SD reader.

 

[skanter]

Your a6400 can't fully utilize UHS-II card.

I use UHS-II V90 SD, and the practical transfer rate to a PC is about 120-180MB/s using a dual CFExpress A & UHS-II SD reader.

Yeah, I just asked perplexity - a6400 cannot make use of UHS-II, only UHS-I speeds. So not worth of it for me to get UHS-II card and reader.

No problem, transfer speed is fine at 50-90 MB/sec.

 

[Sean Nelson]

UHS-I speed has a theoretical max of 104MB/s, so 72 doesn't seem offbase.

I'm not sure that it's the case here, but I get the impression that a lot of people equate the flash memory used in SD cards and the flash memory used in SSDs and therefore assume that they can perform similarly. I can recall reading a post where someone was thinking he could speed up his system on the cheap by installing Windows on a USB-connected SD card instead of a hard drive.

But SD cards have an entirely different internal organization and interface, and really should be treated as apples and oranges. Equating the two would be like expecting hard drives and floppy drives to have similar performance because both use rotating magnetic discs.

 

[New Wrycuda]

Your a6400 can't fully utilize UHS-II card.

I use UHS-II V90 SD, and the practical transfer rate to a PC is about 120-180MB/s using a dual CFExpress A & UHS-II SD reader.

Yeah, I just asked perplexity - a6400 cannot make use of UHS-II, only UHS-I speeds. So not worth of it for me to get UHS-II card and reader.

No problem, transfer speed is fine at 50-90 MB/sec.

That’s a good number of images/sec.

Note that there’s sometimes confusion between megabytes and megabits when comparing transfer speeds. (MB = megabytes, Mb = megabits).

I’ve hardly ever measured actual transfer speeds on my systems, since everything is “fast enough”, including SD cards on a Dell XPS 8940 (now retired*).

I do have a laptop with a microSD slot that is occupied with a 32GB card just for completeness. - It would only be of any use if I wanted to backup some local data while travelling.

* Power supply failure. Computer no longer needed so kept for spare parts.

 

[number_5]

Your a6400 can't fully utilize UHS-II card.

I use UHS-II V90 SD, and the practical transfer rate to a PC is about 120-180MB/s using a dual CFExpress A & UHS-II SD reader.

Yeah, I just asked perplexity - a6400 cannot make use of UHS-II, only UHS-I speeds. So not worth of it for me to get UHS-II card and reader.

No problem, transfer speed is fine at 50-90 MB/sec.

My dad and I was on a birding trip (mass amount of data daily). He was transferring the images from a CFExpress B (max read 3530 MB/s) with a card reader (10Gbs) to a laptop (40Gbs port), and the transfer rate was ~33MB/s. He finally complained about it on the 3rd day. I handed him a different cable, the rate jumped to over 300MB/s. The transfer rate is at the mercy of the weakest component.

OM-5II has a USB-C port, but it's rated 480Mbs (bit and not byte!). Not all USB-C are created equal.