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AMD A10 7850K APU Fauly RAM Controller

pr2thej

pr2thej

pr2thej

Associate
Joined
14 Nov 2009
Posts
52
Throwing this out there, as having spent most the day diagnosing the problem maybe I can save someone some time.

Here's the Build:

A10 7850K APU
Asus A88XM-A Motherboard
2x4GB Kingston Hyper X Beast 2133MHz
Crucial M500 120GB SSD
WD 3TB Green HDD
Be Quiet 350W SFX PSU
Thermaltake AXP100 HSF
Silverstone Milo ML03 Case

Its a solid build overall, bit pricey for what it is but I had some serious space constraints.

Anyway, been building away today and no matter what I did I could not get it to boot stable in dual channel.
Tried a different PSU
Tried upping the NB voltage as high as i felt comfortable with (.2v)
Tried setting the RAM speed timings manually, both at 1600MHz and 2133MHz
Tried different RAM (Corsair 4x8GB XM3 1333MHz)
Tried manually setting the NB Frequency. I dont know much about this but I tried 2400 and that didnt work.

Booting with 1 stick of RAM (any of the above!) is fine.
All RAM is recognised in the BIOS regardless of which slot it is in.

My only conclusion is that the Memory Controller on the APU is faulty, and so I will RMA it. It could possibly be the motherboard stll, but I think the APU is more likely.

If anyone else has experience of this, or another conclusion please feel free to share.
 
I have similar board (Asus A88X PRO) and no problem 2400 MHz in dualchannel 24/7 stable.

Did you got into BIOS? Whats your version of BIOS? Did u load DOCP profile?
 
Thanks for the response. Sorry, I forgot to say yes I did try both DOCP Profiles (1600 and 2133), and also manual settings.
Current BIOS version is 1003, I think thats the stock one actually. I did flash it earlier to latest but cleared the CMOS in a moment of frustration earlier. I am comfortable in ruling the BIOS version out either way.

This thread has leaned me towards the APU being at fault to be honest
http://www.tomshardware.co.uk/answers/id-1852181/asus-a88xm-dual-channel-ram-problem.html


EDIT: NVM, 1003 is the latest BIOS
 
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If its considered relevant, I was just playing Skyrim 1080p@ Medium, and NFS Shift 2 and a bunch of other games with no issue on the one 4GB RAM running at 2133MHz. Temps are fine, power is fine, everything is new.
 
I know on my Gigabyte mobo I had to install the later bios to even put the 7850k in (nightmare), i would try the single RAM in both slots, if that's OK then that stick 'should' be OK, then do the same with the other stick of RAM, if that causes problems then that could be the problem.
If the problem occurs when you swap RAM slots, then it may well be a faulty slot or check the underside of the APU incase a pin is bent.
 
Thanks, have checked all the RAM in all configurations with all XMP profiles and manual timings (and just at default!). That includes my other set of 2x4GB as well so very confident its not the RAM.

It could very well be the motherboard slots, but my thinking is - if I can get single channel to run off any slot on the mobo, and there is no issue recognising any of the RAM then it must be the fault of the memory controller which is responsible for handling dual channel.

Ill be taking off the APU tonight, im just doing as much as I can on the build (XBMC based htpc) over the weekend. If theres no bent pins Ill still be RMAing because I just can't think what else it could be.
 
I have the exact same issue myself with the same configuration. Setting the RAM speed and timings to the slowest provides more stability, but this shouldn't be neccessary.
 
pbrain - brand new install of Win7, all drivers up to date. Some firmware lacking im sure but for nothing critical (SSD etc)

ryanaz, the most stable I can manage is usually the Win7 logo then crash...or very rarely I get a few seconds past the logo. I agree it shouldnt be necessary but knowing what does work is useful for diagnosing the actual fault.
When you say you have the exact same spec do you mean you have the same mobo and same RAM at the same speeds?

Cheers
 
I have the same motherboard & APU, and i've tried it with a variety of different brands/speeds of RAM and they all have same issue. I should mention that my A10-6800k in this motherboard did not have this issue.
 
SOrry, mate - your three components seem to be completely fine (memory, APU and motherboard) as I think.

It's all about QVL (Qualified Vendors List) - it's got huge importance on Asus motherboards, especially toppest ones - but seems like A88XM-A is one of them. Many people forget about it.

QVL:
http://dlcdnet.asus.com/pub/ASUS/mb/SocketFM2/A88XM-A/Memory_QVL_List_for-kaveri-cpu.pdf

And Kingston memory configurator says this memory wouldn't fit as well:
http://www.kingston.com/us/memory/s...ry_for_ASUS/ASmobile_A88X_Motherboard_A88XM-A

I know it's a pain, but until Asus changes its BIOSing policy, it's better to think twice and search for compatible memory instead of having such freezes. I've had similar picky motherboard from Asus, but QVL helped a lot :)
 
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update) i have been scouring the internet and actually contacted a few peopel who have this system configuration in a stable scenario. The only correlation i've found is that it crashes with Windows, NOT in linux or SteamOS.

The issue appears to be with some default windows driver that doesnt work with the a88xm-a / a10-7850k combo.
 
Biuro74 thats really useful mate thanks - light at the end of the tunnel :) I never think to check such things as I always assume that as long as the specs match there should be no problem. Funny how things go.
Ryanaz - sounds logical, although its probably more pain than its worth to hunt down the culprit. I'm glad its not just me though, thats for sure!
 
biuro74 said:
SOrry, mate - your three components seem to be completely fine (memory, APU and motherboard) as I think.

It's all about QVL (Qualified Vendors List) - it's got huge importance on Asus motherboards, especially toppest ones - but seems like A88XM-A is one of them. Many people forget about it.

QVL:
http://dlcdnet.asus.com/pub/ASUS/mb/SocketFM2/A88XM-A/Memory_QVL_List_for-kaveri-cpu.pdf

And Kingston memory configurator says this memory wouldn't fit as well:
http://www.kingston.com/us/memory/s...ry_for_ASUS/ASmobile_A88X_Motherboard_A88XM-A

I know it's a pain, but until Asus changes its BIOSing policy, it's better to think twice and search for compatible memory instead of having such freezes. I've had similar picky motherboard from Asus, but QVL helped a lot :)
Click to expand...

I have the same motherboard, bought in the fall to replace with a Kaveri, that I could not install the Catalyst 13.30 drivers on. My memory is on the QVL. I flashed the BIOS like a good boy and reinstalled Windows 8 during my two days of struggling.

There's something off in ASUS' BIOS for this board. It's not Kaveri. I built a Gigabyte mini-ITX box last week that works just fine.
 
Still waiting on the RMA from ******, not ruling out the CPU being dodgy personally.
But assuming it isnt, I either have to replace the mobo or the RAM. I have RAM lined up from the QVL for the Asus, but its an import from the states and will cost me a pretty penny (not to mention depreciation on the Kingston 2133).

Any tips on an alternative mobo?

Needs mATX FM2+ max 2400MHz RAM and HDMI out. Won't be overclocking.


EDIT: This appears to fit the bill:

http://www.gigabyte.com/products/product-page.aspx?pid=4875#ov

mATX Check
Sata 3 Check
FM2+ Check
2400MHz RAM Speed (oc) Check
HDMI Out Check

One issue I see is that this board wants 1.5v RAM and the Kingston Hyper X 2133 is 1.6v...thats going to knacker my kaveri surely?

Comments or other board suggestions welcomed!
 
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Just to update with an interesting development.
****** have confirmed my original Kaveri as faulty under warranty! After reading this thread I wasnt expecting that but perhaps there is another issue going on here.
 
New Kaveri recieved, installed and experiencing exactly the same problem.
God knows what ****** found! Just going to order an equivalent gigabyte board, see if that solves the issue.
 
I used to think Asus Mobo's was alright, until I bought an EVGA Mobo...blew it out of the water! I would prefer a Zotac over Asus boards given the choice.

I've got a Z68 full ATX Asus mobo with i7 2700k and it's flaky, OC's don't save, USB mouse stop working after a while & have to keep CTRL-ALT-DEL to wake it up.

Also got a Zotac Z68 ITX with i7 2600K, that's OC'd and (touch wood) hasn't skipped a beat!

got a pair of Gigabyte AMD ITX boards (one for the A10-6800k & one for the A10-7850k) and they have been working really well.
 
I have an Asus in my main rig and its never given me any problems. This A88XM-A is utter tripe though I have to say. The latest BIOS (1102) actually makes the situation worse, in that with just the 1 stick of RAM installed I get about 5 minutes of windows desktop as opposed to it being stable.

Cant wait for the Gigabyte board to arrive!
 
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