# 1866MHz RAM on FX-8350 performing extremely poorly



## Slappy420 (Sep 26, 2015)

My specs are in my profile. I was running MAxxMem2 benchmarks playing with my timings when I decided to look at what other people with similar rigs where posting for their results and I am getting almost exactly half of the read,write, and copy speeds. the only thing that is close to what others are posting is my latency. I have all 4 DIMM slots filled and I am certain they are operating in Dual Channel mode. I just cant begin to guess what the problem could be. Thank you in advance for any assistance

MaxxMem2 results
  Memory Copy 11802 MB/s
  Memory Read 12014 MB/s
  Memory Write 6459 MB/s
 Reached memory 9.24 GB/s
 Reached Latency 57.1 ns


----------



## Steevo (Sep 26, 2015)

Download Everest Aida 64 and run a report and post it.


----------



## arbiter (Sep 26, 2015)

that would seem to tell me its running in single channel mode not dual channel.


----------



## DeathtoGnomes (Sep 26, 2015)

I would venture to say there is an "auto" or two missing from view in the BIOS, or one of his mem sticks became a branch without telling him directly.


----------



## HD64G (Sep 26, 2015)

If all sticks aren't of the same model, could be that not being put correctly in pairs diables dual-channel mode. Some mobos don't work with same color slot=same memory channel. I'd swap the sticks to check that.


----------



## DeathtoGnomes (Sep 26, 2015)

HD64G said:


> If all sticks aren't of the same model, could be that not being put correctly in pairs diables dual-channel mode. Some mobos don't work with same color slot=same memory channel. I'd swap the sticks to check that.


Reading the mobo manual about installing memory would note which slots to use. The trick is in assuming everyone reads those manuals that just happen work great as a drink coaster.


----------



## HD64G (Sep 26, 2015)

DeathtoGnomes said:


> Reading the mobo manual about installing memory would note which slots to use. The trick is in assuming everyone reads those manuals that just happen work great as a drink coaster.


I have seen manuals written wrong in how to put sticks to have dual-channel...


----------



## DeathtoGnomes (Sep 26, 2015)

HD64G said:


> I have seen manuals written wrong in how to put sticks to have dual-channel...


exactly, great coasters eh?


----------



## Slappy420 (Oct 10, 2015)

sorry didnt see the reply in my mail. I downloaded Aida64 and ran it and it crashed my rig almost instantly.  The sticks are all a matched set from a single kit of 32GB G.Skill DDR3 Sniper F3-1866C10-8GBSR 10-10-9-28 all channels are filled, everything I can find that reports on memory says its operating in dual channel mode at 1866MHz with the prescribed timings manually set I have nothing on auto all sticks settings are the same


----------



## GorbazTheDragon (Oct 10, 2015)

Tried running the sticks in pairs?

Could be your board getting dodgy if that still crashes.


----------



## cadaveca (Oct 10, 2015)

Normal issue for AMD FX CPUs and having all ram slots filled with 8 GB @ 1866 MHz. Try 1600 MHz. This platform does not fully support more than one stick per channel @ 1866.


----------



## Slappy420 (Oct 12, 2015)

I'll give that a try, I knew that for 2133 or 2400Mhz support you could only use 2 sticks, I didnt know it applied to 1866MHz as well since its listed as the max supported speed by the CPU's memory controller I assumed (my first mistake) that would mean max speed supported with both channels filled. Thank you for the advice. 
 on a side note, would the same hold true for an A10-7850k with 2133MHz ram 16gb 4x4GB sticks (all slots filled)?


----------



## RichF (Oct 12, 2015)

I would try bumping up your NB Core to 1.3V and leaving your RAM at full speed first. If it helps then try to back it down to 1.28, then 1.26. Some boards will automatically increase the voltage with load so it's optimal to find the minimal stable maximum performance voltage value.

You may also want to slightly overvolt your RAM. If it's 1.5V RAM then try 1.6, for instance. AMD's RAM controller is weaker than Intel's and sometimes a bit more voltage can help. If you have 1.65 V RAM I would not go past 1.7, though.


----------



## RichF (Oct 12, 2015)

Benchmarks have found that FX processors can get increased performance from even RAM higher than 1866, provided that it is high-quality very tight timing-to-MHz ratio RAM. I don't think such timings and speeds will be possible with 4 sticks.

Since you're stressing the controller with four sticks, you may want to try to get your RAM to run at 1600 at a lower CAS. CAS 8 would be ideal if you can get it to be stable. Be sure to run 8 copies of Memtest in Windows to quickly rule out unstable settings, prior to serious stress testing. Also, I suggest leaving some physical RAM for the OS when doing Memtest. I typically run 7 threads of around 1.5 - 2 GB and then have the last thread set to a small amount of RAM, like 512 MB.

There is a latency calculation that can help you find the optimal RAM setting in terms of CAS latency vs. MHz. Too much overall latency can undermine any seemingly good combination but too little will lead to Memtest errors. I have found that if I stay within the same approximate overall latency the timings, MHz speeds, and voltages are secondary to that in terms of stability. So, if you know what your board's overall latency number is you can use that to figure out whether or not it will be fairly stable without having to do a lot of initial testing. (Of course, higher MHz settings and tighter timings do tend to increase voltage demands.)

All this said, I tried 4 sticks of RAM in my 970 motherboard machine at 4.5 GHz and I could not get them stable no matter what. That was only 1600 speed RAM (2 GB per stick, double-sided). But it was also two very different sets. One was a 1.35V set and the other was a 1.65V set. Both RAM sets in the machine were fine by themselves but when both sets were put together — nothing — stabilized them. Even setting them to 1066 and 1.5V didn't work. I don't know if I have a bad slot or not because I didn't take the time to do that extra testing. I just bought a higher-capacity RAM set. The motherboard manual seemed to imply that the first set of slots is more reliable so I have a feeling my board doesn't really support 4 sticks with real stability and the second two slots are mainly there for show.


----------



## cadaveca (Oct 12, 2015)

Slappy420 said:


> I'll give that a try, I knew that for 2133 or 2400Mhz support you could only use 2 sticks, I didnt know it applied to 1866MHz as well since its listed as the max supported speed by the CPU's memory controller I assumed (my first mistake) that would mean max speed supported with both channels filled. Thank you for the advice.
> on a side note, would the same hold true for an A10-7850k with 2133MHz ram 16gb 4x4GB sticks (all slots filled)?


Boosted voltages may allow for higher speeds on all AMD platforms for sure, but function is not guaranteed. The APUs have better memory support for sure, but yes, the same still applies (many A88X boards I have suggest using specific slots at anything 1600 MHz or above).


----------



## PCGamerDR (Oct 19, 2015)

Slappy420 said:


> I'll give that a try, I knew that for 2133 or 2400Mhz support you could only use 2 sticks, I didnt know it applied to 1866MHz as well since its listed as the max supported speed by the CPU's memory controller I assumed (my first mistake) that would mean max speed supported with both channels filled. Thank you for the advice.
> on a side note, would the same hold true for an A10-7850k with 2133MHz ram 16gb 4x4GB sticks (all slots filled)?



a10-6800k running 8gb 2x4gb @2368Mhz, memory is capable of 2400 but running lower since i OC'ed with bclock.


----------



## PCGamerDR (Oct 19, 2015)

Slappy420 said:


> My specs are in my profile. I was running MAxxMem2 benchmarks playing with my timings when I decided to look at what other people with similar rigs where posting for their results and I am getting almost exactly half of the read,write, and copy speeds. the only thing that is close to what others are posting is my latency. I have all 4 DIMM slots filled and I am certain they are operating in Dual Channel mode. I just cant begin to guess what the problem could be. Thank you in advance for any assistance
> 
> MaxxMem2 results
> Memory Copy 11802 MB/s
> ...



And also if your ram have the correct timings, volt and what not, try increasing the timings a little bit and see if it's stabilizes, i had issues with my g.skill kits as well, where at their advertised speed they were not stable until i increased its CL from 10 to 11.

Edit: didn't multi-quote since i thought i was talking to different persons xD...


----------



## AlwaysHope (Oct 20, 2015)

cadaveca said:


> Boosted voltages may allow for higher speeds on all AMD platforms for sure, but function is not guaranteed. The APUs have better memory support for sure, but yes, the same still applies (many A88X boards I have suggest using specific slots at anything 1600 MHz or above).



Ah-Ha! , that explains why my A10-7850K on A88X based mobo doesn't like (errors in IBT standard runs) my G.Skill F3-16000CL9D-4GBRH (2000MHz) sticks in slots 2 & 4, even when ram is underclocked to 1866MHz.... but is happy with 1600MHz in those slots with that particular ram...  weird to say the least... and mobo has latest bios too.
The only reason I use those slots is because the silly cpu cooler overhangs the 1st slot and I"m not about to try and remove the heatspreaders from that ram because its just too easy to damage those sticks..


----------



## m0nt3 (Oct 20, 2015)

Running 4*4GB 1866 on my FX 8320 and according to AIDA64 I get, Memory read: 25882; Memory Write 19974; Memory Copy 22785; Memory Latency 22785. my default timings are 9-9-9, but I can do 8-8-8- @ 1866 with all ram slot filled. Guess I was one of the lucky ones? 

http://valid.x86.fr/zes7nu <-CPU-Z validation


----------



## sasamkd (Oct 20, 2015)

Also running 4*4GB 1866 on FX8350 with more or less same results as above. And recently, for a friend, combined A10-7850K + A88X + 2*4GB 2400MHZ Kingston Beast (running on 2133, 1,63V). No problems at all.


----------

