I'm sure most of you have seen that about half a year ago there was an issue found with the performance of the very popular Samsung 840 EVO SSD drives. Read performance can basically crawl to a standstill. I've seen people post about it here on AVSIM and on many other sites on the internet. Samsung say that not necessary all drives are affected and they have posted a fix for this issue on their website. The predecessor 840 (non EVO or PRO) also seems to have the problem but Samsung have not produced a fix or even acknowledged it. I have a 1TB 840 EVO used solely for FSX photo scenery but for various circumstances I've not been using FSX for basically half a year. The other day I finally came around to see if my drive was affected.

 

I ran HD Tune and given this result I could see that my drive was certainly seriously affected:

 

 

Maximum read transfer rate of 16.8MB/sec and worst recorded access time of over 20ms measured on an SSD! I was gobsmacked how badly degraded my drive was!

 

As I've done a lot of storage testing on photo scenery performance before I immediately configured FSX for testing, grabbed my stopwatch and fired up my test. Remember I hadn't started a flight in FSX for half a year. I knew from my previous testing that it should normally take the flight just under 2.5 minutes to load, but after 10 min I started to suspect my computer had crashed as the load screen was still static at the 6% mark. Given the extremely bad HD Tune numbers I decided to stay put and a further 10 minutes later I could stop the clock at 20min 26 seconds to load the flight. That is quite a noticeable real life degradation if you ask me. I did my texture load testing and got 35 seconds. A lot better than I expected actually. That's still better than a Velociraptor HDD but a fully working SSD should yield 25 seconds in this test. Did a bit of flying around and during the limited test it felt like normal, smooth flight apart from that the texture loading was a bit sluggish.

 

I did another 2 tests. 17min 5sec followed by 14min 24sec to load the flight and 31sec followed by 29sec for the texture loading. Performance was obviously improving as the drive started to get used again but it was still horrible. I decided to backup all the data on to an empty SSD I had to prepare to apply Samsung's fix. It took 8.5 hours to copy all the 797GB of data over. That's a transfer rate of a measly 26MB/sec between 2 SSDs on SATAIII. Horrible!

 

After the copy I decided to test the drive once more and it had now settled down to a consistent and more tolerable 2min 44sec to load a flight and 26sec for texture loading. Did a bit of free flying and thought the texture loading looked quite normal again. Ran HD Tune again and it confirmed performance had indeed improved a lot but was still way from where it should be.

 

 

After that I ran Samsung's fix and the good news is that the drive didn't loose any of the data and a quick HD Tune test confirmed that performance was indeed restored to where it should be.

 

 

I ran my FSX test again and to my surprise I got quite a bit faster load times compared to what I got when I tested over half a year ago. Back than the drive had been in frequent FSX use for about a year but had obviously started to degrade already. Pity I didn't run HD Tune to see how the disk performed then.

 

So these are the different results I was getting

 

The degradation mainly manifests itself with longer load times for a flight, but severe degradation also reduces your ground texture loading. 

 

As far as I understand the problem appears on the SSD when the data sits for a long time after it was written, without getting accessed or re-written. If you frequently delete and add data to an SSD you'll end up reading and re-writing a lot of old data as well just because of the way an SSD works in that it can only delete larger chunks of data whilst it can write a lot smaller chunks. That way it prevents the degradation. On the other hand if you, as in my case, use the drive purely for FSX scenery and have already filled it, you will only access a lot  of that data very infrequently. That would be the prime use case to experience degradation.  The fact that my drive hadn't been accessed for half a year and initially displayed extremely poor performance and subsequently had the performance to improve significantly after all data had been read during the backup certainly fits that.

 

The original Samsung 840 drive was the first SSD to use TLC. A new type of SSD technology that offers more storage for your money. It's unfortunately what seems to be the culprit. The original 840 and Samsungs follow-up 840EVO were the only products to use TLC for 2 years until SanDisk released their Ultra II in autumn 2014. Samsung have also released their 3rd TLC drive, the 850EVO. I think these are the only TLC SSDs as of today. The 850EVO however uses a very different type of TLC to the other TLC drives and this type is hopefully more resilient to this problem. All the other manufacturers have announced that they are working on TLC drives for a long while but it seems very tricky to get right.

 

Will my restored drive continue to perform well or will it start to degrade again? I know that the fix re-writes all the data as well as updating how the drive is reading the data through updated firmware. Reports online of disks degrading once again are certainly not reassuring. Re-writing all the data alone should restore the performance initially. Have/will the firmware engineers manage to overcome this problem? Will other TLC SSDs also get this problem? Only time will tell. It has certainly put me off buying another TLC SSD for now.

 

Do you use an 840 EVO and are experiencing ever longer initial load times without having added more to your FSX install? Maybe time to run HD Tune and check how your SSD is performing and it's certainly time to apply Samsung's fix if you already haven't.

 

So you're saying you neglected to apply the fix from Samsung and you're suprised FSX was slow? I downloaded the fix the day it came out.

 

End of problems with slow loading.

So you're saying you neglected to apply the fix from Samsung and you're suprised FSX was slow? I downloaded the fix the day it came out.

 

End of problems with slow loading.

I said I hadn't used FSX since the fix came out. I'd barely used my desktop actually. Hence not applied the fix

Just wanted to show how extremely bad these drives can be if they haven't been updated.

Samsung also say that no data has ever been lost and not all drives are affected (I seriously doubt that having red up on it further now, my guess is that the usage pattern determines if the degradation will show its ugly face or not) so didn't feel any rush to check and update my drive.

 

 

End of problems with slow loading.

Sorry, didn't read this line first. I take it you experienced slow loading as well before applying the fix on your 840EVO?

 

Have you checked if the disk has started to degrade again after the fix?

 

That's what worries me the most if it starts to degrade again. They might have been cheep in SSD terms but still payed a lot of money for the disk.

Yeah I checked all that the day the report came out

 

My load times were slow on the SSD. My read times werent quite as low as your numbers but pretty close.

Yeah I checked all that the day the report came out

 

My load times were slow on the SSD. My read times werent quite as low as your numbers but pretty close.

Always good to get it verified that others experience the same. Glad to hear that the fix works for you as well.

 

Do you use your EVO purely as a sim drive basically only reading off the drive or do you write and delete a lot on it as well? I suspect that we flightsim users that use the EVO drives purely as a SIM drive are in pole position for drive degradation

Thanks very much for taking the time to post your extensive report. I have an 840 Evo and it was only through reading posts similar to yours that I became aware of the issue. I applied the fix but have also read reports that this is not necessarily a run and forget process and that some users have experienced performance degradation even after having run the fix and have had to run it again.

Interesting results thanks for sharing.

 

I use a Plextor M5Pro for my flightsim drive and have no complaints, very fast and reliable for 2 years now.

 

Also been using a Samsung 830 as my laptop drive for 2 years and no problems with it either. 

Always good to get it verified that others experience the same. Glad to hear that the fix works for you as well.

 

Do you use your EVO purely as a sim drive basically only reading off the drive or do you write and delete a lot on it as well? I suspect that we flightsim users that use the EVO drives purely as a SIM drive are in pole position for drive degradation

 

I use it for FSX, P3Dv2.5, XP10, FSX:SE (installed but now in use), and Battlefield 4.  All my addons for the sims are installed on it (840 Evo 500GB)