DH55TC extremely slow with RAM over 8GB

[rolfe]

Hi guys, I built a computer with DH55TC, I3 560, a pair of 2GB Kingston PC3-10700 (667 MHz) and a 2GB SATA3 disk. So far, it runs fine under Windows 7 64 bit and does what it should. Then I went on to increase the memory to please Photoshop with it. I bought two more Kingston PC3-10700 (667 MHz) modules, this time with 4 GB each. Now: I can use these RAMs in whatever combination only up to 8 GB. Whenever I increase the size over 8 GB (i.e., 10 or 12, no matter which slots), the system boots and works, but extremely slow. Win 7 boot takes around 10 minutes. In tests with memtest86+ the combined memory does not result in a memory error. But: Whenever the combined size is over 8GB the last part of each test runs extremely slow. I mean the following: Memtest shows which part it is testing, 1 to 2048, 2048 to 4096 and so on. All runs are fast, besides the last one, whenever this is beyond 8 GB. Has anybody an explanation for this? Has it to do with memory mapping? For the tests I used the usual "e820" method and it always shows the exact size. What is wrong with this mainboard?

Thanks for any answer!

Rolf

 

[jaquith]

Welcome to Tom's Forum!

It's not the RAM it's that you mix-matched the RAM, the Speed, CAS Timings, Voltages, Type incl' chips/side all have to be the same other wise the BIOS disables the RAM as being 'defective' to prevent errors.

In addition, you ONLY want to buy RAM in matched sets of 2 or 4, and then only install them per the manual in the appropriate DIMM channel slots.

[strike]Q - What MOBO?[/strike] Intel DH55TC
Q - What EXACT RAM? ; please post a link to the RAM

 

[rolfe]

Welcome to Tom's Forum!

It's not the RAM it's that you mix-matched the RAM, the Speed, CAS Timings, Voltages, Type incl' chips/side all have to be the same other wise the BIOS disables the RAM as being 'defective' to prevent errors.

In addition, you ONLY want to buy RAM in matched sets of 2 or 4, and then only install them per the manual in the appropriate DIMM channel slots.

[strike]Q - What MOBO?[/strike] Intel DH55TC
Q - What EXACT RAM? ; please post a link to the RAM

Thanks for answering, jaquith. The Kingston Product Number is KVR1333D3N9/4G for the 4GB modules and KVR1333D3N9/2G for the 2GB modules. They are of the same type and both are recommended for the Mobo. And, as I wrote, all RAMs are working, but only as long as the combined size is not more than 8 GB. Therefore I assume that the source of the problem lies elsewhere.

Rolf

 

[jaquith]

KVR1333D3N9/4G http://www.valueram.com/datasheets/KVR1333D3N9_4G.pdf
1333Mhz timing of 9-9-9 at 1.5v
KVR1333D3N9/2G http://www.valueram.com/datasheets/KVR1333D3N9_2G.pdf
1333Mhz timing of 9-9-9 at 1.5V

I assume the RAM is being installed -> CPU | 4GB | 2GB | 4GB | 2GB |
I assume that they were purchased as 'Matched Sets' and NOT individually?!

Just because the BIOS sees the DIMM slot doesn't necessarily mean the BIOS enables the RAM to be processed to the CPU and available to the OS. Often as density goes up the DIMM voltage requirements go up, and if there's not enough power to the DIMM slots you also get as described.

BIOS:
DRAM Voltage -> 1.5~1.6v
DRAM Frequency -> 1333 MHz
QPI/DRAM Voltage -> 1.25~1.3v {CPU/VTT, IMC Voltage ; CPU Memory Voltage}
CAS Timings
/9-9-9

 

[rolfe]

The 2GBs are pairs, the 4GBs are not bought as pairs. The RAMs do not make problems as long as they are used within a sum of 8GB. That means, the two 4 GB work together and the pair of 2GBs works together with either one of the 4 GBs and similarily all other smaller configurations. When I combine the two 4 GB modules together with one or both 2 GBs they get extremely slow, but still work.

After your post I increased the RAM voltage from 1.5 to 1.6 for a test, but without success, same situation as before. I also tested a reduction of the timing from 1333 MHz to 1066 MHz: No difference. The only somewhat amazing observation with the mainboard were sudden changes in voltage Vcc of the processor. It changes suddenly between .89 and 1.2 without any obvious reasons. Although these values are well within limits, the changes seem somewhat abrupt. Is that usual?

Rolf

 

[jaquith]

Explanation, the voltages vary as the CPU Multiplier varies and isn't unusual. Run Prime95 and they'll stay or 'should' stay very level under full load.

Regarding the RAM, with none matched pairs I'm not surprised -- at all really.

Try the following combo, no guarantees:
installed -> CPU | 4GB | 4GB | 2GB | 2GB |

If the problem persists then exchange/sell the unmatched 4GB for new Tested per RAM Mfg SETS.

 

[satishb]

Hi Rolf,


I had faced this issue with my DH55TC motherboard and after updating the BIOS, it got resolved.

So try this update the motherboard BIOS, it may work for you as well.

You can download the latest BIOS update from this url 'http://tinyurl.com/d56zjlu' and file is TCIBX10H.86A.0048.EB.EXE and install it.

Satish

 

[rolfe]

Hi Satish,

good to hear and thanks for this info. I exchanged the motherboard long ago against a Asus P8H67-V that works fine with my RAMs (I was pretty sure about that in advance....).

But I still own the Intel board and the processor, may be I will mount it again in a suitable case when prices for disks get better again! It could fournish a good home file server with a small power consumption.

Rolf