(Computer won't turn on) / How to overclock A10-7850K's memory controller

[Slobodan-888]

Memory controller in AMD A10-7850K only supports up to 2133 MHz RAM (stock). I have RAM that is factory guaranteed to work at 2400 MHz. In order to utilise its full potential (I use integrated GPU) I need to overclock memory controller.

How can I do that? I can't find any option for thin in a BIOS (latest version).

My motherboard is Gigabyte GA-F2A88XM-D3H

And if I would to contact a manufacturer, should I contact AMD or Gigabyte about this?

 

[truegenius]

it won't beep when not using keyboard, its normal it atmost may show that keyboard not found and nothing else ( that if you get display )

try to get single beep sound ( post ) using only smps + ram + cpu + motherboard ( disconnect every thing else, monitor too, but do not remove cpu fan or heatsink )

this will eliminate any other component as a cause

 

[Slobodan-888]

As far as I remember, if the keyboard is not plugged in (when computer was working) it did beep.

I have tried only APU, RAM, motherboard and PSU (practically the only components I have, besides HDD and some PCI card for printer port). No beep. It only beeps when I remove RAM. I have not tried without APU (because removing the cooler is not easy at all, and I will destroy rubber fan mountings).

P.S. Strange thing. I have measured short between power pins of BIOS nad RTC chips, but when I power the computer on, I get 3,3 V for BIOS and 5 V for RTC chip...

 

[truegenius]

you don't need to boot it without apu, it won't help and won't even run as this is the critical component

no beep while ram isn't in and beep while ram is in means ram is causing the post to not complete sucessfully

only way is to get atleast some spare ram without xmp profile ( or jedec equal to xmp in clock speed )

 

[Slobodan-888]

I have measured voltage ripple of the PSU while computer was "on".

For 5 V rail it was like 170 mVpp, which is fine.

For 3.3 V rail it was about 120 mVpp, which is also fine.

Now, for 12 V rail, it was 650 - 700 mVpp to 1,2 Vpp when PSU changes its mode of operation.
So that is 10% voltage ripple max for the 12 V rail. That is within acceptable values, right?

P.S. Like couple years ago, I have changed output filter electrolytic capacitors in the PSU. I installed high-quality, long lifespan at high temperatures Japanese ones (Panasonic, Rubycon , United Chemi-Con, Nichicon). So they will outlive any other components in the PSU.

 

[Slobodan-888]

Well, it does not beep while RAM is in. And I don't have any spare one.

 

[Slobodan-888]

Here it states the max ripple values:

50 mVpp for +5 V and +3,3 V
120 mVpp for +12 V

https://en.wikipedia.org/wiki/ATX#Power_supply

Is this true? Because if it is, than it could be the power supply. But I still doubt that, it is good DTK PSU with changed high-quality caps. And I doubt that PSU suddenly failed in this aspect just after reseting BIOS.

 

[Slobodan-888]

I have took out PSU and measured ripple under load (using adjustable dummy load).

890 mA - 328 mVpp
1 A - 336 mVpp
1,25 A - 384 mVpp
1,5 A - 456 mVpp

then PSU changes its work regime (I can hear different frequency of buzzing):

2,14 A - 448 mVpp
2,22 A - 448 mVpp

2,22 A is maximum for this load.

 

[Slobodan-888]

+ 5V rail
------------------------
100 mA - 96 mVpp
500 mA - 158 mVpp
750 mA - 194 mVpp
1 A - 218 mVpp
1,25 A - 218 mVpp
1,5 A - 224 mVpp
1,6 A - 220 mVpp

+ 3,3 V rail
-----------------------
100 mA - 68 mVpp
250 mA - 94 mVpp
500 mA - 122 mVpp
750 mA - 136 mVpp
1 A - 110 mVpp
1,15 A - 112 mVpp
1,74 A - 74 mVp

 

[Slobodan-888]

I need schematics for DTK Computer PTP-4007P. It is a 400 W ATX power supply.

 

[Slobodan-888]

Well, the PSU is bad (a lot of ripple) and I can't seem to fix it. Plus I don't have an ESR meter to check the output caps, so...

I will have to take the computer to some local service (repair shop) so they can try working PSU in it, to see whether it is just the PSU fault (I hope).

 

[Slobodan-888]

I have tried new PSU, and computer behaves the same. I will have to take it to the service, where it will sit for weeks...

 

[cdrkf]

I have tried new PSU, and computer behaves the same. I will have to take it to the service, where it will sit for weeks...

It could be a failed processor, I would normally say it's the motheboard however in this case all the logic that was being tweaked was on the CPU itself. I guess you don't have another compatible processor to throw in and check it?

 

[Slobodan-888]

I don't have any other FM2/FM2+ CPU/APU. But I doubt that it is the processor. Yes, I have been overclocking NB (which is integrated in APU), but I have returned everything on factory settings for APU. Only thing that I have changed was turbo-boost frequency (from 4.0 to 4.2 GHz).

I have been only tweaking RAM settings. NB was at stock settings.

I think that it is the BIOS chip (both of them). But we will see.

APU, motherboard and RAM are all still under warranty.

 

[Slobodan-888]

I am back from holiday and computer is back from service. They changed the motherboard.

Now, about memory. I will keep it at 2133 MHz, but instead of CL11 I want to set it to CL10 or CL9 if possible.

According to this: http://www.techpowerup.com/reviews/Kingston/HyperX_Beast_Black_2133_C11/8.html

At about 1,8 V it could run at 2133 MHz and CL9. Now, what about other latency settings?

It is now at CL11-13-13. If I want to change it to CL9-?-?, what should I set insetad of "?".

Also, how much will this increase the RAM bandwith?

P.S. According to the memmory chip datasheet (SK Hyunix H5TQ4G83MFR) absolute maximum voltage is 1,975 V, so 1,8 V is fine.

 

[cdrkf]

I am back from holiday and computer is back from service. They changed the motherboard.

Now, about memory. I will keep it at 2133 MHz, but instead of CL11 I want to set it to CL10 or CL9 if possible.

According to this: http://www.techpowerup.com/reviews/Kingston/HyperX_Beast_Black_2133_C11/8.html

At about 1,8 V it could run at 2133 MHz and CL9. Now, what about other latency settings?

It is now at CL11-13-13. If I want to change it to CL9-?-?, what should I set insetad of "?".

Also, how much will this increase the RAM bandwith?

P.S. According to the memmory chip datasheet (SK Hyunix H5TQ4G83MFR) absolute maximum voltage is 1,975 V, so 1,8 V is fine.

Changing the CL for the ram will improve latency but NOT bandwidth. Essentially what your doing is reducing the amount of cycles it requires to access a specific point in the memory array, which at the *same frequency* (cylces per second) reduces the time to access. It doesn't however increase the actual throughput though so bandwidth will stay the same.

I believe lower latency can be useful in many CPU related tasks so it will be an improvement, but I think it has virtually NO impact on graphics performance. Having said that I've never really compared so I'll be interested if you could run a benchmark on the iGPU before and after the change (never know it might bump it up a few points). I'd recommend you get 3D Mark off steam for comparison.