<p>The slowest USB standard is &quot;low-speed USB 1.0&quot;, at 1.5 megabits per second.  The slowest SD card I've been able to find has a rated read speed of 900 kilobits per second.</p>
<p>The average line of G-code is about 200 bits.  Even the slowest USB connection or SD card can transfer thousands of lines of G-code per second, much faster than your printer can carry out the relevant motions.  Any speed difference is going to come from how a printer handles those data sources, not anything inherent in them.</p>

CC BY-SA 4.0
2024-01-23T10:42:09.367Z
I'll accept this answer because you specifically also mentioned 'Any speed difference is going to come from how a printer handles those data sources, not anything inherent in them'. Although helpful, the answer is limited to a comparison of the specification speeds of the USB an SD standards alone, and does indeed not take into account how a particular printer handles those data sources which could still greatly affect the outcome. I'll try to do some tests on Creality Ender 3 V2 in particular and post the results here later.
Bob Ortiz
CC BY-SA 4.0
2023-12-28T03:57:51.167Z
2023-12-28T04:20:42.743Z
2023-12-28T04:20:42.743Z
Mark
<p>I've been repeatedly printing the same G-code on two fairly identical machines (Creality Ender 3 V2) with the same settings, the only difference being one is printed from a Micro SD card and one is printed using OctoPi over a USB cable.</p>
<p>Although I didn't measure the exact times, I have the idea that the SD card prints were consistently faster.</p>
<p>Is it possible that prints from Micro SD card are indeed faster than prints sent from OctoPrint and if so, by how much percent could it be and why?</p>

CC BY-SA 4.0
2023-12-27T22:04:24.263Z
For the percentage, why do you ask us instead of printing a beanchie on the same machine twice, once via usb and once via microsd, and measuring?
Mołot
CC BY-SA 4.0
2023-12-27T22:21:18.003Z
I will once my printers are not printing. But I'm more interested in the theory behind it and if, why and how this could be the case.
Bob Ortiz
<g-code><usb><microsd><sd>
Is printing from a micro SD card faster than printing over a USB cable?
Bob Ortiz
# Is printing from a micro SD card faster than printing over a USB cable?

(Asked by: username_0 on 2023-12-27)

I've been repeatedly printing the same G-code on two fairly identical machines (Creality Ender 3 V2) with the same settings, the only difference being one is printed from a Micro SD card and one is printed using OctoPi over a USB cable.

Although I didn't measure the exact times, I have the idea that the SD card prints were consistently faster.

Is it possible that prints from Micro SD card are indeed faster than prints sent from OctoPrint and if so, by how much percent could it be and why?

**Tags:** g-code, usb, microsd, sd
> **Comments:**
> **username_1**: For the percentage, why do you ask us instead of printing a beanchie on the same machine twice, once via usb and once via microsd, and measuring?  
> **username_0**: I will once my printers are not printing. But I'm more interested in the theory behind it and if, why and how this could be the case.  

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## 1 answers

### Answer by username_2 on 2023-12-28. Score: 4 | Accepted answer

The slowest USB standard is "low-speed USB 1.0", at 1.5 megabits per second. The slowest SD card I've been able to find has a rated read speed of 900 kilobits per second.

The average line of G-code is about 200 bits. Even the slowest USB connection or SD card can transfer thousands of lines of G-code per second, much faster than your printer can carry out the relevant motions. Any speed difference is going to come from how a printer handles those data sources, not anything inherent in them.

> **Comments:**
> **username_0**: I'll accept this answer because you specifically also mentioned 'Any speed difference is going to come from how a printer handles those data sources, not anything inherent in them'. Although helpful, the answer is limited to a comparison of the specification speeds of the USB an SD standards alone, and does indeed not take into account how a particular printer handles those data sources which could still greatly affect the outcome. I'll try to do some tests on Creality Ender 3 V2 in particular and post the results here later.  

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