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CMP4GX3M2A1600C8 rated at 1067 MT/s ?


Kyoto

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Hi There !

 

I have a system with Intel DX48BT motherboard, Intel Q9550 Quad CPU and 2x2Gb RAM of Corsair CMP4GX3M2A1600C8.

 

Front Side Bus is 1600 Mhz and memory runs at 1600 Mhz XMP 8-8-8-24 2T

DIMMs are installed in black slot 1 in dual channel symetric mode as specified by mainboard specifications that support 1600 Mhz ( Intel Tech. spec. for DX48BT2)

 

With any banchmark I test the memory SiSoftware and Everest I get a bandwith of only ~ 8.5 Gb/s which corresponds to Intel's XMP specificaton

of FSB 1600 and DRAM 1067 MT/s. = 8.5 Gb/s single and 17 Gb/s dual

 

The memory modules are marked and sold as PC3-12800 and also max bandwith reported from SiSoftware is 12.8 Gb/s for this memory modules.

 

Eventhou I cannot get this memory modules to run at 1600 FSB 1600 MT/s data rate which would be 12.8 Gb/s in ideal situation.

 

FSB Voltage 1.20 V, MCH voltage on MB is 1.25 V and CPU Voltage is 1.2875 V but I dont think this is the problem.

 

Can you please provide me some more information on this topic, either I have setup something wrong or the modules does not specify requirements PC3-12800.

 

thanks, regerds, Kyoto

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Here are also the timings set:

 

CAS Latency (CL) 8T

RAS To CAS Delay (tRCD) 8T

RAS Precharge (tRP) 8T

RAS Active Time (tRAS) 24T

Row Refresh Cycle Time (tRFC) 88T

Command Rate (CR) 2T

RAS To RAS Delay (tRRD) 6T

Write Recovery Time (tWR) 22T

Read To Read Delay (tRTR) Same Rank: 4T, Different Rank: 7T

Read To Write Delay (tRTW) 8T

Write To Read Delay (tWTR) Same Rank: 2T, Different Rank: 7T

Write To Write Delay (tWTW) Same Rank: 4T, Different Rank: 7T

Read To Precharge Delay (tRTP) 8T

Write To Precharge Delay (tWTP) 22T

Precharge To Precharge Delay (tPTP) 1T

Refresh Period (tREF) 16383T

DRAM Read ODT 3T

DRAM Write ODT 7T

MCH Read ODT 8T

Performance Level 8 (MemSet shows ChA pref. level 7 and ChB perf. level 8 )

 

Read Delay Phase Adjust Neutral

DIMM1 Clock Fine Delay 8T

DIMM2 Clock Fine Delay 8T

DIMM3 Clock Fine Delay 0T

DIMM4 Clock Fine Delay 0T

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Thanks for reply Wired,

 

Yes I did. The motherboard DX48BT2 has a native support for 1600 FSB ( Intel Spec. )

and CPU overclocked without any issues. System is 100% stable and RAM appears to run

at 1600 Mhz ( at least system reports this ) but DRAM data transfer rate is not 1600 MT/s

but 1067 MT/s which corresponds to memory clock 133 Mhz ?

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Memory tab shows it runs at 800Mhz DDR3 Dual Symetric

SPD shows max bandwith PC3-10700H (667Mhz) which could be the JEDEC value and not XMP I suppose.

MemSet 4.1 reports DDR2 ( but I think this one has some compatibility issues ?)

and I dont think it reads correct values.

memory.jpg.93ddec563925abae7500adfcc0285b9f.jpg

SPD.jpg.5b393ab69d0a754bcd1d4125a05a426c.jpg

memset.jpg.eb06a06a4daaf7d3573792cb1255565e.jpg

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Here are also timing sets read from different programs:

( in case this would be problem and XMP profile is not loaded properly )

 

Everrest:

9-9-9-24 (CL-RCD-RP-RAS) / 34-74-1-5-10-5-5 (RC-RFC-CR-RRD-WR-WTR-RTP) JEDEC

8-8-8-24 (CL-RCD-RP-RAS) / 41-88-2-6-12-6-6 (RC-RFC-CR-RRD-WR-WTR-RTP) XMP

 

CPU-Z:

CL-tRCD-tRP-tRAS-tRC-CR @ frequency (voltage)

XMP #2 8.0-8-8-24-41-2T @ 800 MHz (1.650 Volts)

 

Min tRFC 110.00 ns

Min tRRD 7.50 ns

Min tWR 15.00 ns

Min tRTP 7.50 ns

 

SiSoftware

9-9-9-24 (CL-RCD-RP-RAS) / 34-74-1-5-10-5-5 (RC-RFC-CR-RRD-WR-WTR-RTP) JEDEC

actual:

8-8-8-24 (CL-RCD-RP-RAS) / 32-*-2-6-12-*-8

 

MemSet 4.1

8-8-8-24 (CL-RCD-RP-RAS) / *-88-2-6-*-18-8 (RC-RFC-CR-RRD-WR-WTR-RTP)

 

BIOS:

8-8-8-24 (CL-RCD-RP-RAS) / *-88-2-6-10-6-6 (RC-RFC-CR-RRD-WR-WTR-RTP)

 

Hope there will be some answers to this topic.

 

regards, Kyoto

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I read this post in detail and I see a lot of similarity with my problem:

http://forum.corsair.com/v2/showthread.php?t=72919

 

except one thing, the BIOS and System reports that RAM runs at 1600 Mhz

or at 1600 MT/s but in fact it runs @ 1066 Mhz or 1067 MT/s as specified.

 

The question is if possible to Corsair stuff:

 

I had checked compatibility with DX48BT2 board on:

 

http://www2.corsair.com/configurator/product_results.aspx?id=530593

 

and purchased those modules at price of 120,00 EUR for 2x2Gb so I expected them to run at specified values.

 

I know there is a lot of discussion either modules or mainboard but as said if they are on compatibility list ...

 

But they don't even run at 1333 Mhz with FSB 1333 while I am getting performace of a 6.4 Gb/s at this settings which is much worse than any average of 10,5 Gb/s eventhou MCH and CPU shoud preform much better in this scenario.

 

So what would be the verdict, are those modules compatible, or should I trade them and try something else.

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  • Corsair Employees

The X-48 Intel chipset is old and all of these questions should be directed at Intel. This is just the limitation of that chipset and why the next generation of Intel chipsets had much better memory performance at the same clock frequencies. There is nothing wrong with the memory, and running them at DDR1600 requires you to over clock the CPU on this MB as you cannot run the memory frequency faster than the CPU FSB.

I would suggest testing them on an an Intel Core I5/I3 MB to see the difference. And you should contact Intel about the limitations of this specific MB.

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I hope that you check this screenshots and tell me what is wrong with this picture:

 

** My assumtion is that MEM runs at predetermined frequency non-dependant of MEM settings in BIOS and that this frequency is 1066 Mhz, why I do not know that is why I ask you.

 

Screenshot: mem380.jpg, fsb380.jpg ( changed FSB to 380 in BIOS, not changed any MEM settings )

 

Screenshot: mem333.jpg, fsb400.jpg ( restored FSB to 1600, changed MEM to automatic, 1333 Mhz 9-9-9-24 1T CPU-Z still reports 1600 Mhz MEM: WRONG )

 

I also addded Intel chipset specifications and you can clearly see that Data Rate of this modules on this X48 is exactly 8.5 Gb/s which corresponds to FSB 1600 MHz and Data Transfer rate of 1067 MT/s as specified in tabele.

 

xmp_configuration.jpg

 

 

I tested this modules also on another system with Intel Core I5-760 with loaded XMP profile @ 1600 Mhz BLCK 160, CPU 3520 Mb/s and getting results of 17.0 - 18.5 Mb/s data transfer rate

 

Which somehow corresponds to 8.5 Gb/s on X48 ( either dual channel or x2 CPU threads test )

 

My point here is not to explain either those modules work properly or not, thats why you are here I guess.

 

I'd like to get the system full running and buying those modules with 1.65 V for X48 might be a mistake, but since thay run stable an without any other issues I still think that this was right decidion if I could load XMP profile or run them on 1333 Mhz

 

for information I had DDR2 modules with same cpu on P35 mainboard running @ 800 Mhz and provided 7,2 Gb/s bandwith with limitation of PC2-6400 but cannot get run those modules on MB which officialy supports 1600 MT/s or PC3-12800 past 8.5 Gb/s

 

Please check this info and hope you repond to solve this problem.

 

thanks, regrads, Kyoto

mem380.jpg.76de2275b57180ccd9c8d2d57b0a2407.jpg

fsb380.jpg.435a90b0b64f151c1b696f6f82d710ea.jpg

mem333.jpg.bc76740b6a4d338bdccfd9716ea2dc10.jpg

bandwith-test.JPG.78bdca2ab456b3f13a0eb78841019f7b.JPG

xmp_configuration.jpg.1f61c0e6bde07054a8934dea1eecfbc6.jpg

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  • Corsair Employees

Kyoto

You should do a little more research on over clocking this chipset and the answer will start to become more clear.

 

But in a nut shell the reason you are getting an odd frequency when you run CPU-Z is because the CPU Frequency is set to 380 MHz with an odd multiplier and the MB or chipset does not support DDR1600 Natively.

In addition, the theoretical band width is just that. IE this chipset and every chipset has its limitations. Again I would speak with Intel they should be able to address that question better than we can.

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Hi thanks for reply,

 

I don't need more than 1600 FSB on this mobo and running CPU @ 3.4 Ghz which was not a problem at all while "officialy" this borad supports 1600 FSB natively, if "non officaily" is not supported I would not know.

 

The reason I went to X48 chipset is that I needed PCI 2.0 support and DDR3 support with same CPU. It was maybe not most rational decision but I explicity chose X48 chipset which "should" natively support 1600. I am not the guy who would test each and every Voltage on borad but get it simple.

 

I did plain and simple, get the board which supports 1600 FSB (natively) get the board which support 1600 MT/s natively get the RAM which support XMP profile 1600 Mhz and that is it.

 

Don't need anything more than that and board/CPU runs fine and stable with 1600 FSB and CPU overclocked from 2.8 to 3.4 Ghz.

 

I assume, but eventhou I am IT consultant ( with not every detail knowledge in every HW on the market ), that somehow SPD values are not read correctly and XMP value is not read by bios proprely.

 

I am getting XMP (profile) read in BIOS as 1.9V and not 1.65 V eventhou other settings 8-8-8-24-2-88-6-12-6-6 might be correct, but cannot verify.

 

When I tried Intels Desktop Center I got I constant error XTU:

XMP profile cannot be initilized ?!

 

and here is logical conclusion if at 1600 FSB cannot get 1600 MT/S from run it drops to 1067 MT/s as specified by Intels XMP docu.

 

and all the test suggests that this corresponds to bottleneck of 8.5 Gb/s or PC3-8500 rating.

 

Please give me an updated info and/or suggestions what could/should be done in this case.

 

If you "would say" ,no this RAM is only for i5 Intel processors and we cannot help you I am fine, but please lets clear this question either should I loose more time in testing and trying with this modules or should I say I blew it by buying those for x48 board.

 

thanks, regards, Kyoto

 

p.s. I am reading forums and testing things for quite some time now. read all intel official docu. for X48. My last resort is always official support forum that is why I am here now.

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Your memory is running at 800MHz, which is DDR1600.

 

attachment.php?attachmentid=8541&d=1306705924

 

Your memory is at DDR1600 and at the timings listed above. It is running as it is specified to run. The memory is doing what it is supposed to do.

 

Please, in concise simple terms, what is it that you want?

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This is screenshot which I posted before.

 

BIOS

FSB 1600 MHz, MEM: 1333 Mhz at timigs 9-9-9-24 1T 1.5 V (?)

 

XMP profile should be @ 8-8-8-24 2T 1.65 V otherwise it dose not work, you know that

 

CPUZ reports 800 Mhz with 1333 timimings and voltage set to 1.5 V in BIOS

this cannot be correct:

 

CPU-Z reports FSB value and not MEM Value in this case.

 

MEM tested with 1600 Mhz on 1600 FSB should preforem in up to 12.8 Gb/s

data transefer rates and not at 8.5 Gb/s data transfer rates.

 

That is my point.

mem333.jpg.5c4c59f3d2fe33c6a99bb1aba805c8e2.jpg

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XMP profile should be @ 8-8-8-24 2T 1.65 V otherwise it dose not work, you know that

 

CPUZ reports 800 Mhz with 1333 timimings and voltage set to 1.5 V in BIOS

this cannot be correct:

 

CPU-Z reports FSB value and not MEM Value in this case.

 

 

Your memory is running at 800MHz, which is DDR1600, not DDR1333.

 

attachment.php?attachmentid=8541&d=1306705924

I think you are missing something here. The MEMORY tab on CPU-Z shows your DDR rate. Your memory IS operating at its rated specifications of DDR 1600.

 

MEM tested with 1600 Mhz on 1600 FSB should preforem in up to 12.8 Gb/s

data transefer rates and not at 8.5 Gb/s data transfer rates.

 

That is my point.

 

First, 12.8Gb/s is a theoretical maximum, not a guaranteed specification.

 

Second, our memory is running at the rated speed. If your bandwidth is not satisfactory, that is the fault of the memory controller, NOT THE MEMORY. As RAM GUY has stated multiple times, you need to contact Intel if you are not satisfied with the performance of their memory controller.

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I posted my last picture once more while apparently you have not seen it or ignored it.

 

:confused: How do you explain that this RAM runs 1600 Mhz @ 9-9-9-24 1T 1,5 V

 

But never mind..

 

I will test with another set of 1600MHz certified RAM which is designed at JEDEC 1.5 and Extention of 1.7 -1.9 V and post results here.

 

If I don't brake the magic barrier of 1066Mhz or PC3-8500 standard with significant difference in data rate than I'll go complain at Intel.

 

regards, Kyoto

mem333.jpg.580e7bdf75748a45a11b9e64a9a7e2ed.jpg

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801MHz = DDR1602. Both of your pictures show the same frequency. This is NOT DDR1333. It's DDR1600.

 

attachment.php?attachmentid=8560&d=1306882178

 

I must admit to being confused. I cannot understand what it is you are asking or what you expect from this memory.

 

Also, when the memory frequency is set to 333 in the BIOS, that changes in a proportional amount to how much you raise your FSB. So, once you overclock to 1600 on the FSB, your memory frequency goes up also.

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It's already been explained more than once that bandwidth is theoretical, NOT an absolute standard. IF his equipment is not hitting those numbers, it's due to the memory controller and not the memory.

 

Also, there is some confusion. Check the CPU-Z reading notes in red above. It's a 1333 FSB CPU, not a 1600. When you OC the CPU, the memory frequency goes up accordingly.

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Thanks for all the answers.

 

I came also to conclusion that MCH must be the case to slow down the data rate, eventhou it was never expected form my side to hit 12.8Gb/s while this is practicaly impossible.

 

And I guess that Q9550 CPU as YB has figured out must be the problem.

 

It has native 333 FSB, overclocekd to 400 FSB impacts the MCH in a way that MCH instead of 1600 MT/s uses first lower value according to XMP specification from intel which is 1067 MT/s

 

So my opinion is ( i cannot confirm this ) that if CPU with native 1600 FSB would be used such as QX9xxx data rate would be higher.

 

thanks, regrad, Kyoto

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So my opinion is ( i cannot confirm this ) that if CPU with native 1600 FSB would be used such as QX9xxx data rate would be higher.

 

thanks, regrad, Kyoto

 

I do not think this is correct. The MCH is the same for each type of CPU, a 1333 FSB or 1600 FSB. One simply runs faster than the other and will pass Intel's standards at stock settings. An OCed 1333 CPU+MCH at 1600 is the same as a stock 1600 CPU+MCH. Your limitation is still the MCH.

 

If you absolutely need to have more memory bandwidth, a socket 1366 or socket 1155 system is your best option.

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