Iryon Posted February 12, 2017 Share Posted February 12, 2017 Hi guys, I'm new here and it's my first thread/post. I just bought a chinese usb pendrive of 1TB on my last gig in Shenzen, It's marked SanDisk and pretends to be USB 3.0 but I knew that I would eventually faced some problems. I noticed that after loading several gigabytes some contents were corrupted and I immediately looked for information about this problem becoming aware of the AIDA64 program for testing. I did a first benchmark with Random Write + Verify, It took an entire day of work but in the end there were no errors. I would bet that the test would be interrupted in order to find his true capacity, and unmask the distorted controller. I'm here to asking what can i do more than this. I tried the Linear Write + Verify but it takes days to complete. Quote Link to comment Share on other sites More sharing options...
Fiery Posted February 12, 2017 Share Posted February 12, 2017 3 hours ago, Iryon said: Hi guys, I'm new here and it's my first thread/post. I just bought a chinese usb pendrive of 1TB on my last gig in Shenzen, It's marked SanDisk and pretends to be USB 3.0 but I knew that I would eventually faced some problems. I noticed that after loading several gigabytes some contents were corrupted and I immediately looked for information about this problem becoming aware of the AIDA64 program for testing. I did a first benchmark with Random Write + Verify, It took an entire day of work but in the end there were no errors. I would bet that the test would be interrupted in order to find his true capacity, and unmask the distorted controller. I'm here to asking what can i do more than this. I tried the Linear Write + Verify but it takes days to complete. Linear Write + Verify shouldn't take days to complete, as long as the drive performs at least as good as an average USB 2.0 pendrive. Even if the drive can do only 25 MB/s, filling the drive and verifying it would take "only" 23 hours. In case the drive performs considerably worse than that, that fact alone would make one suspicious about authenticity of the pendrive... BTW, a true USB 3.0 pendrive would do at least 100 MB/s, and so it would complete the Linear Write + Verify test in 6 hours (considering it's a 1TB capacity drive). 1 Quote Link to comment Share on other sites More sharing options...
Iryon Posted February 12, 2017 Author Share Posted February 12, 2017 Thank you for the answer. UPDATE: Meanwhile i tried some more tests with another application and it has been reported data loss after 14,3 Gigabytes so maybe I found the real capacity of the pendrive. The writing speed detected is about 2,75Mb/s and the reading speed is about 8,87Mb/s so that's why my Linear Write + Verify has just reached the 20% after 12h. Surely the pendrive is defective, but what can i do to fix things? Quote Link to comment Share on other sites More sharing options...
beeonline Posted February 13, 2017 Share Posted February 13, 2017 Fiery, is it possible that the Randon Write + Verify test does not reveal any errors on a drive that has less capacity than advertised? Quote Link to comment Share on other sites More sharing options...
Fiery Posted February 13, 2017 Share Posted February 13, 2017 20 hours ago, Iryon said: Thank you for the answer. UPDATE: Meanwhile i tried some more tests with another application and it has been reported data loss after 14,3 Gigabytes so maybe I found the real capacity of the pendrive. The writing speed detected is about 2,75Mb/s and the reading speed is about 8,87Mb/s so that's why my Linear Write + Verify has just reached the 20% after 12h. Surely the pendrive is defective, but what can i do to fix things? I'd simply return the device and ask for a full refund due to a suspected fraud. I wouldn't try to fix the drive at all. Even if you could format it to its "right" capacity, the performance would still be abysmal. 1 Quote Link to comment Share on other sites More sharing options...
Fiery Posted February 13, 2017 Share Posted February 13, 2017 5 hours ago, beeonline said: Fiery, is it possible that the Randon Write + Verify test does not reveal any errors on a drive that has less capacity than advertised? If the drive has a very smart controller that desperately tries to hide the fact that the capacity is less than the advertised value, then for a while the Random Write + Verify test may not report any issues. Especially when the performance is that freakishly low With such an underperforming drive you would have to let the Random Write + Verify test run for at least 2 days to draw any meaningful conclusion. Good old fraudulent pendrives which perform adequatly (like 20-30 MB/s) are usually caught by the test in a matter of minutes, sometimes few seconds only. But it's always best to let the Linear Write + Verify test to complete to 100%, since that's the only sure way of knowing that the drive can be filled 100% with data, and all data is fully retained (stored) by the drive. 1 Quote Link to comment Share on other sites More sharing options...
beeonline Posted February 14, 2017 Share Posted February 14, 2017 @Fiery: Ok, thank you. @Iryon: I saw that you posted the same question in a comment to the related post on the Italian AIDA64 blog. Now that you talked to the dev in person here I will not post a reply there if you don't mind. Buona giornata! 1 Quote Link to comment Share on other sites More sharing options...
Iryon Posted February 14, 2017 Author Share Posted February 14, 2017 22 hours ago, Fiery said: I'd simply return the device and ask for a full refund due to a suspected fraud. I wouldn't try to fix the drive at all. Even if you could format it to its "right" capacity, the performance would still be abysmal. The return is a bit difficult because I live thousand miles away from Shenzen. I bought the device at a fake market so I knew somehow what I would expected but for the price I just wanted to try it as a portable device, not a main storage device. Maybe I'll try the Linear Write with a laptop because I'm looking for an accurate analysis. I also trying to find a good firmware to flash but I didn't find the one yet. These chinese have done a very good job 4 hours ago, beeonline said: @Iryon: I saw that you posted the same question in a comment to the related post on the Italian AIDA64 blog. Now that you talked to the dev in person here I will not post a reply there if you don't mind. Buona giornata! Ok, thank you as well Quote Link to comment Share on other sites More sharing options...
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