[ursine]

Hi, I have a three weeks old Samsung EVO 840 500GB that has the notorious bug. Read speed has dropped to 58MB/s for the three weeks old files using HD Tune Pro (see the attached three benchmark comparisons). I want to replace the Samsung EVO by Scandisk Extreme Pro.Then I had the following chain of misfortunate:

1. I cloned EVO 840 to a new Scandisk Extreme Pro using Macruim Reflect. Everything seems fine except the read speed of Scandisk Extreme Pro was about 375Mb/s much slower than the advertised 500Mb/s mark. So I tried to secure erase it and do a clean install. Acronis indicated that over 3 hours was needed to complete secure erase and I didn't want to wait and cancelled it in the middle of process. Then I did a quick format instead and the Scandisk Extreme Pro was "bricked" suddenly. The PC cannot see it with my USB-SATA adaptor.

2. Next I bought a new Crucial M500 240GB. This time I used Acronis to clone the EVO. Again the HD Tune benchmark of the cloned M500 is very poor, at 150MB/s , slower than my Seagate mechanical hard drive.

3. I did a quick format of the M500 and installed window 8 from fresh. The HD Tune benchmark of clean installed SSD is as bad as the cloned SSD. So the poor performance is nothing to do with cloning.

My system is Asus Hero VII 4790K GTX 970 16GB RAM. There are 8 x 6GB/s SATA ports. I tried manual trim but it makes no difference.

I do not understand why both Scandisk Extreme Pro and Crucial M500 are so both slow on my system. I am completely puzzled. Any advice would be appreciated. My last option is not to replace the EvO and wait for the Firmware update on the 15th .

 

[ursine]

Hi, I haven't tried it. It looks like I will be stuck with the crappy EVO and wait for the firmware update. I do not understand how the poor performance of the Samsung EVO can pass to two other different SSDs or I must have very bad luck Everything I touch it turns into crap.

 

[ursine]

I am not confident enough to try the Diskfresh fix, in case it will do more harm than good. If Samsung firmware is not a reliable fix, I will send my EVO back and get another Sandisk Extreme Pro. My dealer has accepted the return of the EVO but offered to replace it by another new EVO. But I said no and thank you. No wonder they have dropped the prices of EVO by a massive amount yesterday.

 

[ursine]

yeah I will never secure erase new or old drive in the future. Painful lesson learnt. I thought it would be safe after reading about people secure erase their SSDs in forums. There should be a warning message in Acronis that secure erase can instantly turn your $160 drive into a door stop.

 

[ursine]

Then I have no clue how I physically killed a SSD by interrupting a secure erase and tried to quick format it. The SSD was completely dead but very warm while it was connected to a SATA USB adaptor.

The HD Tune benchmark of the Crucial M500 seems to inherit the performance degradation of the Samsung EVO after cloning. Quick format does not remove the crap in M500 inherited from the Samsung EVO bug. While the benchmark of the Sandisk Extreme Pro remains very flat and consistent, it also suffered from performance degradation in the cloning process. The more I think about, the less it makes sense. It remains a mystery until Samsung is open about the root of the problem.

 

[ursine]

I did make sure no program was running on the background when I ran HD Tune Pro benchmark tests. Asus bios always set the SATA mode to AHCI by default. The motherboard has only 6GB/s SATA ports. Trim is always enabled by default so I cannot think of any external factor that may cause HD Tune Pro to show such bizarre results.

 

[ursine]

I am glad that I am not alone. My problematic Samsung EVO HD Tune benchmark looks very good now and it is snappy like a new drive after restoration. I still cannot explain why the Crucial M500 does not perform consistently across the graph. I think the Scandisk Extreme Pro SSD benchmark looks disappointing becuase I ran the HD Tune when the CPU was at idle frequency. I agree with you. My 2TB 7200 rpm hard drive has rather consistent and clean HD benchmark with maximum read 200MB/s at the outer rims of the platter. I don't get so much grief from HHD with unpredictable and inconsistent performance issues lke the SSD.