Samsung 840 EVO Slow Sequential Read Speeds

[Cpt Underpants]

I just bought a 500gb Samsung 840 EVO about 2 weeks ago. Did a fresh Windows 8 Pro install as is best practice with new SSDs. Since getting the drive I have experienced consistently low sequential read speeds on the Samsung Magician benchmark. Most of my PC use is gaming so sequential reads are the most important performance metric to me. I get sequential read/write speeds in the GB/s range when enabling RAPID mode, but I think the issue is still there but covered up by the RAM caching. I am still under 30-day warranty if I need to return the drive.

Here is a picture of the bechmark:

I installed the latest Intel RST driver when I reinstalled windows. Could there be another driver I am missing or is outdated that could be causing the issue?

System Specs:
i5 3570k
ASRock Z77 Extreme 3
8gb Hyper X 1600Mhz
GTX 760

 

[Dereck47]

You are obviously connected to a 6Gb/s port; connect the SSD to the other 6Gb/s port on your motherboard and see if that helps.

 

[Cpt Underpants]

You are obviously connected to a 6Gb/s port; connect the SSD to the other 6Gb/s port on your motherboard and see if that helps.

Hi, I've tried this. I have a second WD Blue 1tb connected to the second intel 6Gb/s port and I have tried switching them. The results are exactly the same, with everything fine except for the same slow sequential writes.

I followed all the SSD optimizations and OS changes for windows 8 in this guide:
http://www.overclock.net/t/1240779/seans-windows-8-install-optimization-guide-for-ssds-hdds
To be specific:
- shrunk the page file using "powercfg -h -size 75" in command prompt.
- shrunk page file (512mb initial up to 2000mb maximum)
- shrunk system protection disk usage to 1%
- disabled GUI on boot
- enabled write back caching and turned off windows write-caching buffer flushing

Could any of these changes be affecting sequential reads?

Is it possible that upgrading to windows 8.1 did something? My original windows 8 Pro install disk was purchased before 8.1 came out, so I updated to 8.1 after my fresh windows 8 install. I never did a speed check before updating, and now I'm curious if it would have been different.

 

[Dereck47]

It's possible but I doubt upgrading to Windows 8 or 8.1 is causing your problems.

Run 'OS Optimization' in Samsung Magician. Run for 'Maximum Performance'. Reboot your system and then run the benchmark again.

As a last resort before you decide to rma the drive, if you have a old version of Windows (Win 7), then do a fresh install of it and rerun the benchmark.
If your Sequential Reads are higher then that would confirm that the problem is with Win 8 or 8.1 and not your SSD.

 

[Cpt Underpants]

Unfortunately I dont have another copy of windows to try as this is my first pc build and I use a MBP for school.

What makes me apprehensive to RMA is that when i run crystal disk and AS SSD benchmarks the performance shows up normally as it should (ie 500+ mb/s seq reads & writes). I don't know why the samsung magician benchmark is seeing sub optimal sequential reads. This isn't normal and doesn't make sense to me.

 

[Dereck47]

Oh, I didn't know that; If you're getting advertised Read/Write speeds from AS-SSD & CrystalDiskMark then I would consider the drive to be just fine.

AS-SSD & CrystalDiskMark use highly incompressible data to test Read/Write speeds. Highly incompressible data is the hardest type of data for any SSD to Read/Write.

I'm having some issues with version 4.4 of Samsung Magician myself. I'm on a AMD chipset and my SATA ports are in RAID mode (2 HDDs in RAID-0), and RAPID mode does not work for me with version 4.4. So I have to continue to use version 4.3 in order to use RAPID mode.

 

[Cpt Underpants]

Thanks for your help. So you think it's safe to assume it's the magician software bugging out? Sorry if I seem persistent I just want to be sure my drive isn't underperforming before my warranty is up.

 

[JohnnyLucky]

I've been reading posts about Samsung 840 EVO benchmarks and low sequential reads. I keep looking for some sort of pattern or common denominator. What I see is actually an omission. Individuals who ask questions and the responses completely ignore the Magician's ssd optimization. Selecting the high performance option and OS optimization is often mentioned. I have yet to see anyone recommend the Magician's ssd optimization. What it does is force trim and garbage collection. Normally that should restore optimal performance. Samsung uses passive garbage collection which means it waits for idle periods or periods of very little activity before it initiates garbage collection.

Please run ssd optimization and let us know what happens.

Dereck47 - You probably already know this but Samsung designed their ssd's for use with Intel based systems. Samsung does not recommend their ssd's for AMD based systems; however, they should be okay. There have been a small handful of reports about odd behavior. You already know about RAID arrays which Samsung does not recommend either despite the positive reviews. Samsung's rapid mode is not yet complete. They're still working on it. It should be complete when Samsung releases their new 850 EVO in the very near future. Rapid mode can use up 25% of a system's DDR3 memory providing the OS does not need it. However, it is temporarily capped at 4GB. My system has 32GB that I use for experimenting with RAMDISKS. The current Magician recognizes and indicates that I have more than 4GB available but it is still capped at 4GB. Samsung is working on bumping it up to the full 25%.

 

[Cpt Underpants]

I've tried the optimization many times. It completes in a few seconds and doesn't do anything for performance. Be even run trim manually through the disk manager in windows 8. The drive is new and isn't even half full. It gets lots of idle time between use and it just doesn't make sense that garbage collection or trim have something to do with this unless I'm missing something.

 

[JohnnyLucky]

Slapping myself upside the head. My suggestion was for improving write performance not read performance. Don't know what I was thinking. I must have had another one of those senior citizen moments. I am growing old disgracefully and I forget stuff.

 

[Cpt Underpants]

haha no worries