Reviewed in the United States on March 29, 2018
Ordered this from Amazon/PNY. It came it the well-known PNY-branded packaging that read "up to 95 MB/s." I confirmed that it does READ at 95 MB/s. I also confirmed that it was indeed a 128 GB memory card, (which shows up as 119 GB depending on how you count what a GB is).
EXPLANATIONS.
1) Why do some people document much-slower-than 95 MB/s read time? Well, because it depends on how your device is interacting with it. If you copy one ginormous file, say, 64GB, and it is written sequentially without fragments, and your device is dedicated to NOTHING BUT transferring the file, then you will see 95 MB/s read time. What if you're moving 64GB worth of data, but it's spread out among 200,000 files? Then every time you start to read and copy a new file, the device has to search for the filename in the file allocation table, (FAT), get the address of the file, and then go to that address, and follow pointers wherever that file is physically stored, jumping around as necessary. When it gets to the next file name, it will stop, go to your drive or memory where you're copying it TO, make a new entry in your FAT table, (okay, this is the somewhat simplified version), and then go back to the memory card and search, etc. IN SHORT, the greater number of files and folders you have, and the more scattered, (fragmented), those files are, then the more time the device will spend searching, writing file names, i.e., things OTHER THAN transferring data. That will report as a slower effective transfer rate, even though the memory card is performing at 95 MB/s. SECONDLY, if the device is doing other things on its bus, then clearly transfer time will slow down. Every time the device performs a task, it is reading/writing to/from memory locations, which require transfers over the bus. Somewhat simplified, but the bus is like lanes of traffic. Even if the memory card is reading at 95 MB/s coming out of its own parking garage and driveway, if the interstate (the device's bus) is clogged up with traffic from watching a movie, searching on the Internet, scanning for viruses, etc., then the data from the card is not going to arrive at 95 MB/s, even though it's capable of pumping the data to the interstate (bus) that fast.
2) WHY ONLY 119 GB? DID I GET RIPPED OFF?
No.
Remember, computers only know 2 numbers (or states: on or off). They follow a base-2 system. Let's start by asking what is a kilobyte? Every grade-school kid who learns the metric system knows it's a thousand bytes. They are right. Sort of. To a computer, a kilobyte is 2^10 bytes. Count it out with me: 2, (times 2 is), 4 (times 2 is) 8, 16, 32, 64, 128, 256, 512, 1024. To a computer, a kilobyte is 1024 bytes, not 1000 bytes. So what is a megabyte? In common parlance, it's a million bytes, 1,000,000 bytes. But to a computer, a megabyte is 2^20 bytes. Count it out with me, starting with a kilobyte: 1024 (times 2 is), 2048 (times 2 is), 4096, 8192, 16384, 32768, 65536, 131,072, 262,144, 524,288, 1,048,576. So to a computer, 1 MB is 1,048,576 Bytes, even though we say it's 1,000,000 Bytes. A gigabyte (GB) is what we commonly call a billion bytes. But to a computer, instead of 1,000,000,000 B, a GB is actually 1,073,741,824 B. What we call 128 GB means 128,000,000,000 Bytes to us. But to a computer, 128 GB is 2^37 B, which is 137,438,953,472 B. So when you purchase 128 Billion Bytes of storage, you can call it 128 gigabytes, where "giga-" means "a billion." To understand how many "computer GB" this is compared to "human GB," simply divide by the ratio of 2^37 to 128 Billion, which is 137,438,953,472 divided by 128,000,000,000. You shoudl get 1.073741824. And when you divide it into 128 Billion Bytes, you get 119.2092896, which rounds to 119 GB (computer GB). SO YES, YOU PURCHASED 128 BILLION BYTES of memory, or 128 GB, which THE COMPUTER SHOWS AS 119 GB.
