Two sticks of RAM performing like one stick.. kind of?

Angel Zodiac · Nov 21, 2015

So, this entire thing is really confusing, and I honestly have no idea what's wrong in this scenario.

Hardware:
Motherboard: Gigabyte 990xfa-ud3 (revision 4, updated to F3 bios)
CPU: Phenom II x4 970 BE (overclocked to 4Ghz, though problem exists and is worse when stock clocked - though not by much)
GPU: GTX 970
PSU: Corsair 700w
RAM: Corsair Vengeance 1600 Mhz 2x4GB Model number: CMZ8GX3M2A1600C9

So, what I'm noticing is that in benchmarking software such as performance test, the two sticks of RAM when separately benchmarked pull their weight and are within proper limits. The problem is noticed whenever I have both sticks of ram (regardless of slot/stick combination) installed at the same time. I supposedly only gain an increase of 30%, which isn't the case with the other RAM listed in the benchmarking tool - they seem to double or more in performance going from 4GB to 8GB.

I've checked and the memory is compatible with this motherboard, but the problem exists on both the F2 and F3 bios versions.

I still have to run memtest, but is there truly anything wrong with the sticks themselves here.. or what? I just don't know how exactly this can make any kind of sense. By all means, I'll try anything and any advice would be helpful.

http://i.imgur.com/Iw229uo.png
"Both sticks" is in dual channel in slots 1 and 3, the others are self explanatory and when I had just the second ram stick in slot 1, the results were practically identical. Dual channel in 2 and 4 provides relatively the same as 1 and 3. I'm going to do a bit more testing with different sticks in different slots, but feel free to leave a reply, thanks!

I know the CPU is relatively "old" and only supports 1333 Mhz ram, so is it possible my CPU is bottlenecking this RAM in some fashion? The performance is similar in a benchmark environment if it's running at 1333 or 1600.

bailojustin · Nov 21, 2015

The reason is your CPU
The number of controllers: 1
Memory channels: 2
Channel width (bits): 72
Supported memory: DDR2-1066, DDR3-1333
DIMMs per channel: up to 2
Maximum memory bandwidth (GB/s)
Bus speed - 667 MHz Memory controller
One 2000 MHz 16-bit HyperTransport link (4 GT/s)

You are going to get the best out of 2 dual channel 1333mhz ram sticks, any higher and its to fast for your FSB and your CPU resulting in slower speeds, thats why with 1 stick you see great results as it utilizes the 2000mhz transport
Using your 1600mhz ram, if wanting to use both stick dual configthe memory controller Needs to be adjusted
Drop your RAMs from 800 to 667
Drop your HT Link from 10x (2000MHz) to 8x (1600MHz)
Lock PCIe to 100MHz
Leave NB/IMC at 10x (2000MHz)
Bump NB volts to 1.25v
Drop CPU multiplier to 15x
Raise Clock (FSB) to 240MHz
Set CPU volts at 1.4125

HT Link = 8x240MHz
IMC/NB = 10x240MHz
RAMs = 6.67x240MHz
CPU = 15x240MHz

This will drop your CPU to 3.6ghz, but you can tweak that my tiny voltage increments to the vcore, your main goal is to utilize that 240mhz and build around it. Tighten the timings on your ram until stable and walla you have a real well OC and performing computer.

Since you have the B edition your CPU is locked, so when you raise it it will leave the ram at its frequency, that is why 1333mhz is absolute best for this, at 1333mhz you can stable overclock your CPU, once you have reached what you want, tighten your timings. The cpu will work best with lower frequencies and tight timings for faster relay of communications to the CPU and Ram.

Basically the reason you drop your ram to 1333mhz or 1006mhz is because when you raise the FSB this will raise the clock of your CPU to what you want it to be while also raising the ram from 1333mhz to 1559MhZ.
Also 1333mhz ram at c7 latency is as fast as 1600mhz at c9 latency, so once you are done be sure to drop those timings down TIGHT. if you want a slightly higher CPU like up to 4ghz, you can go for the FSB to 250, that will bring your CPU to 3.8ghz and your ram to slightly higher then 1600mhz.

Another way quoted by LOWJACK-
You can change the vcore and the FSB..when doing this type of OC you will need to underclock your ram to 1333 MHz as raising the FSB will result in raising the entire system clocks, example: lower RAM to between 1066-1333, then raise your FSB to say 240x16= 3.84GHz, and this will result in the RAM clocks being raised to 1599 MHz...raise vcore also IMO I would start out at 1.45v for the above scenario..or in the 1066 MHz scenario I would raise the FSB to 250X16 this will result in a 4.0GHz CPU and RAM at 1333 MHz I would set your RAM timings in this case to at least CAS 7 as CAS 9 1600 MHz is roughly equal to CAS 7 1333MHz RAM..I hope this helps

BTW..FSB also affects the HT and NB , so set your HT and NB clocks accordingly as well keep them around 2000 MHz - 2400 MHz...Essentially the FSB acts as the volume button for the entire system

Angel Zodiac · Nov 21, 2015

bailojustin :

There's a slight problem with your FSB overclock solution, the multiplier doesn't work very well on this motherboard+cpu combination for whatever reason. On the F2 bios version, I was able to use the multiplier to overclock only the first core, the others were unaffected by it. After updating to F3, changing the multiplier doesn't change anything anymore.. so I'm not really sure what to do about all of that.

Would leaving the multiplier at 17.5 and the FSB at 229 (what I'm currently using) or somewhat similar to try to reach 1333 Mhz sufficient?

Angel Zodiac · Nov 21, 2015

bailojustin :

Well, I tried everything you said, except I left the FSB at 229 and the RAM was at ~1220 Mhz (so as to not go above 1333). That, along with downclocking the HT actually decreased the benchmark result, and the reverse, upclocking the HT and having the Ram run at ~1560 made the benchmark quite a bit higher (though still a lot lower than other 8GB sets of Ram). My CPU is stable at 4Ghz, but this whole underperforming RAM thing is concerning. If I was to upgrade to an FX 8350, would this issue magically disappear?

bailojustin · Nov 21, 2015

Angel Zodiac :

So, this entire thing is really confusing, and I honestly have no idea what's wrong in this scenario.

Hardware:
Motherboard: Gigabyte 990xfa-ud3 (revision 4, updated to F3 bios)
CPU: Phenom II x4 970 BE (overclocked to 4Ghz, though problem exists and is worse when stock clocked - though not by much)
GPU: GTX 970
PSU: Corsair 700w
RAM: Corsair Vengeance 1600 Mhz 2x4GB Model number: CMZ8GX3M2A1600C9

So, what I'm noticing is that in benchmarking software such as performance test, the two sticks of RAM when separately benchmarked pull their weight and are within proper limits. The problem is noticed whenever I have both sticks of ram (regardless of slot/stick combination) installed at the same time. I supposedly only gain an increase of 30%, which isn't the case with the other RAM listed in the benchmarking tool - they seem to double or more in performance going from 4GB to 8GB.

I've checked and the memory is compatible with this motherboard, but the problem exists on both the F2 and F3 bios versions.

I still have to run memtest, but is there truly anything wrong with the sticks themselves here.. or what? I just don't know how exactly this can make any kind of sense. By all means, I'll try anything and any advice would be helpful.

http://i.imgur.com/Iw229uo.png
"Both sticks" is in dual channel in slots 1 and 3, the others are self explanatory and when I had just the second ram stick in slot 1, the results were practically identical. Dual channel in 2 and 4 provides relatively the same as 1 and 3. I'm going to do a bit more testing with different sticks in different slots, but feel free to leave a reply, thanks!

I know the CPU is relatively "old" and only supports 1333 Mhz ram, so is it possible my CPU is bottlenecking this RAM in some fashion? The performance is similar in a benchmark environment if it's running at 1333 or 1600.

And again your CPU dosent support 1600mhz thats why its needed to underclock to 1333mhz, but with efficient changes you can get the same results if not way better.

bailojustin · Nov 21, 2015

Angel Zodiac :

bailojustin :

Well, I tried everything you said, except I left the FSB at 229 and the RAM was at ~1220 Mhz (so as to not go above 1333). That, along with downclocking the HT actually decreased the benchmark result, and the reverse, upclocking the HT and having the Ram run at ~1560 made the benchmark quite a bit higher (though still a lot lower than other 8GB sets of Ram). My CPU is stable at 4Ghz, but this whole underperforming RAM thing is concerning. If I was to upgrade to an FX 8350, would this issue magically disappear?

If you were to upgrade to that processor, your life would be 10x easier. then everything on your board is supported and you can OC freely without worrying about bottlenecking your ram speeds with your CPU frequencies.

Angel Zodiac · Nov 21, 2015

bailojustin :

The reason is your CPU
The number of controllers: 1
Memory channels: 2
Channel width (bits): 72
Supported memory: DDR2-1066, DDR3-1333
DIMMs per channel: up to 2
Maximum memory bandwidth (GB/s)
Bus speed - 667 MHz Memory controller
One 2000 MHz 16-bit HyperTransport link (4 GT/s)

You are going to get the best out of 2 dual channel 1333mhz ram sticks, any higher and its to fast for your FSB and your CPU resulting in slower speeds, thats why with 1 stick you see great results as it utilizes the 2000mhz transport
Using your 1600mhz ram, if wanting to use both stick dual configthe memory controller Needs to be adjusted
Drop your RAMs from 800 to 667
Drop your HT Link from 10x (2000MHz) to 8x (1600MHz)
Lock PCIe to 100MHz
Leave NB/IMC at 10x (2000MHz)
Bump NB volts to 1.25v
Drop CPU multiplier to 15x
Raise Clock (FSB) to 240MHz
Set CPU volts at 1.4125

HT Link = 8x240MHz
IMC/NB = 10x240MHz
RAMs = 6.67x240MHz
CPU = 15x240MHz

This will drop your CPU to 3.6ghz, but you can tweak that my tiny voltage increments to the vcore, your main goal is to utilize that 240mhz and build around it. Tighten the timings on your ram until stable and walla you have a real well OC and performing computer.

Since you have the B edition your CPU is locked, so when you raise it it will leave the ram at its frequency, that is why 1333mhz is absolute best for this, at 1333mhz you can stable overclock your CPU, once you have reached what you want, tighten your timings. The cpu will work best with lower frequencies and tight timings for faster relay of communications to the CPU and Ram.

Basically the reason you drop your ram to 1333mhz or 1006mhz is because when you raise the FSB this will raise the clock of your CPU to what you want it to be while also raising the ram from 1333mhz to 1559MhZ.
Also 1333mhz ram at c7 latency is as fast as 1600mhz at c9 latency, so once you are done be sure to drop those timings down TIGHT. if you want a slightly higher CPU like up to 4ghz, you can go for the FSB to 250, that will bring your CPU to 3.8ghz and your ram to slightly higher then 1600mhz.

Another way quoted by LOWJACK-
You can change the vcore and the FSB..when doing this type of OC you will need to underclock your ram to 1333 MHz as raising the FSB will result in raising the entire system clocks, example: lower RAM to between 1066-1333, then raise your FSB to say 240x16= 3.84GHz, and this will result in the RAM clocks being raised to 1599 MHz...raise vcore also IMO I would start out at 1.45v for the above scenario..or in the 1066 MHz scenario I would raise the FSB to 250X16 this will result in a 4.0GHz CPU and RAM at 1333 MHz I would set your RAM timings in this case to at least CAS 7 as CAS 9 1600 MHz is roughly equal to CAS 7 1333MHz RAM..I hope this helps

BTW..FSB also affects the HT and NB , so set your HT and NB clocks accordingly as well keep them around 2000 MHz - 2400 MHz...Essentially the FSB acts as the volume button for the entire system

I understand, but you didn't read any of what I posted last time. I *cannot* use the multiplier whatsoever. It's locked at 17.5 after I updated my bios, and before that three cores besides the first core were unaffected by the multiplier in the bios.

bailojustin · Nov 21, 2015

Angel Zodiac :

bailojustin :

There's a slight problem with your FSB overclock solution, the multiplier doesn't work very well on this motherboard+cpu combination for whatever reason. On the F2 bios version, I was able to use the multiplier to overclock only the first core, the others were unaffected by it. After updating to F3, changing the multiplier doesn't change anything anymore.. so I'm not really sure what to do about all of that.

Would leaving the multiplier at 17.5 and the FSB at 229 (what I'm currently using) or somewhat similar to try to reach 1333 Mhz sufficient?

One of the reasons why you keep the FSB around 240-250 is its the sweetspot for 1333mhz ram, keeping these multipliers will result in better results and more stability. You also want to keep your dram to fsb ratio a non decimal, like 1:4 or 1:8 and so on

Angel Zodiac · Nov 21, 2015

bailojustin :

Angel Zodiac :

One of the reasons why you keep the FSB around 240-250 is its the sweetspot for 1333mhz ram, keeping these multipliers will result in better results and more stability. You also want to keep your dram to fsb ratio a non decimal, like 1:4 or 1:8 and so on

That's great, and I'd love to do that but like I said, I can't set the multiplier to 15x with a 240 FSB, as my CPU (for whatever reason) doesn't register the change in multiplier and tries booting at 17.5x240, which doesn't let my computer boot. The best I was able to boot right now is 175x235, but the DRAM ratio is 3:8 (which I assume isn't good?) so, I guess back to somewhere around 230?

bailojustin · Nov 21, 2015

Alright since your locked at 17.5, go with what you suggested, change the FSB to 230 and the ram back to 1333mhz, 667. this will bring your ram to 1534

bailojustin · Nov 21, 2015

what voltage is your ram at right now?

bailojustin · Nov 21, 2015

Oh and im so sorry, I forgot to mention that you did disable cool and quiet and all other power saving options while doing your overclocks yes?

bailojustin · Nov 21, 2015

On the Gigabyte MOBOs there is a CPU Clock Control line that is set to AUTO above the CPU frequency Line in the BIOS that must be changed to Manual before it will allow changes to the CPU Frequency - changiing the CPU CLock Control to Manual instead of Auto will then allow changes to the CPU frequency to be entered

please let me know when you did this

Angel Zodiac · Nov 21, 2015

bailojustin :

Yeah, all power saving options were disabled long long ago.

Now, should I be clocking my ram down with the multiplier so it's below 1333 or does it not matter if I leave it at 1534? With my ram at ~1250 (having the multiplier -1 for ram) and 7-7-7-21 timings, it performs a bit worse than 1534 at 8-8-8-21 (I've never messed with timings, so I assume these are fine. The computer wouldn't boot with the Cas latency below 8 at 1534). The voltage on my ram is just 1.5v, it boots fine with the timings set to 8-8-8-21 but I haven't done any sort of stability testing.

Angel Zodiac · Nov 21, 2015

bailojustin :

I don't have a "CPU Clock Control" in my bios above the frequency line, all I have there is the multiplier setting (if that's what you're referring to) and like I said before, it doesn't do anything with my CPU.

Angel Zodiac · Nov 21, 2015

bailojustin :

http://www.modders-inc.com/gigabyte-990fxa-ud3-rev-4-0-motherboard-review/4/ This is exactly what my bios looks like, except there are a few things missing due to having a older CPU presumably.

bailojustin · Nov 21, 2015

Angel Zodiac :

I am guessing one of the thing missing is in the advanced CPU control, the Unlock CPU above Cool and Quiet? and this means that your CPU is locked at 17.5 multiplier? what is your ram multiplier currently at?

Angel Zodiac · Nov 21, 2015

bailojustin :

No, actually, I have the CPU Unlock option, but I have no idea what it does besides making all my CPU related temperature readings become 0... Which is really odd. Tested it, doesn't allow the multiplier to interact with the CPU whatsoever. My Ram multiplier is 6.66, resulting in ~1534 Mhz

bailojustin · Nov 21, 2015

okay make sure that CPU unlock is enabled, disable the turbo boost, disable anything that will help, HPM mode, APM mode, and the C states, After unlocking the cpu you should be able to change the CPU clock ratio am I correct or does it still not do anything and just revert back to normal? is it stuck at 17.5, if it is then check your ram, just go ahead and change it to 667, and the multiplier to make it equal 1600 or 1534, if it is 1534 then drop the voltage to 1.5 and keep the block speed 230, tighten your timings as tight as they can get and still allow you to boot. I have been reading and OC that processor past 4ghz is one hell of an accomplishment, but by underclocking the ram to 1333mhz you should be able to get much better readings and benchmarks, after you find your ram stable and timings are great, go ahead and start adjusting your HT to the proper settings to handle the ram at its timings, you was the FSB; DRAM as close to 1:1 as possible, the best you might be able to get is 1:4 or 1:2 and thats fantastic, then using benchmarks and stress tests keep pushing your block speed till you hit the 1600mhz and the CPU GHZ you want, this will also require you to do tiny voltage boosts to your CPU, BUT MAKE SURE IT DOES NOT EXCEED the TWP of the processor or your MOBO slot. as you increase your FSB your going to have to increase all other voltages around it, like the NB and the HT. also if your ram has XMP see what its voltage is in XMP and see what the frequency is.

Angel Zodiac · Nov 21, 2015

bailojustin :

Yeah, none of those options help with the multiplier, so FSB overclocking is the extent of this chip. I'm glad that a bit above 4Ghz stable is an accomplishment for this xD It runs a bit on the hot side, which can't be good for it, but I'm not really concerned about its life expectancy (~61 to 62c max under any real world load with the stock fan). I've never messed with the HT or ram timings, so do you think you could give me a bit more information on what I'm doing with these? I'm going to keep the FSB at 230, as that's the absolute max my computer likes, so how exactly do I get the DRAM close to 1:1? What exactly affects that ratio?

As for the voltage of my CPU, I have it set to 1.4625, and I'm not keen on going any higher than that. Apparently, people have been able to overclock their 970s with 1.5v, but I'm a bit hesitant to put that much into it, especially with stock being 1.4v.

bailojustin · Nov 22, 2015

What you can do is increase the ht link frequency to 2600 from 2400 and the CPU NB frequency up to 2400 from 2200, then you slowly start tightening the ram timings, add a bit of voltage to the ram, bring it from like 1.5 to 1.55 or 1.65 AT MOST.

Your DRAM voltage should never be more than 0.5 V above VTT, or it could cause system stability problems. Since the default VTT is 1.1 V, this means that your DRAM voltage shouldn't be higher than 1.1 + 0.5 = 1.6 V--unless you also increase VTT. So if you're using memory that has a default voltage of 1.65 V or you've overclocked to that amount, you should increase your VTT voltage to at least 1.65 - 0.5 = 1.15 V. VTT is also known as IMC, QPI/VTT, QPI/DRAM.

The four main ram timings are usually listed as something like:
7-8-7-24

However, if you list the timings by their nicknames instead of numbers, it would look like:
tCL-tRCD-tRP-tRAS
Start off by lowering the first (tCL) and third (tRP) timing by 1. If this passes one round of Memtest86+, try lowering the second timing (tRCD) by 1 and running the test again.
eep doing the previous procedure until you've gotten the second timing (tRCD) as low as possible. Once you've done that, start decreasing only the first (tCL) and third (tRP) timing by 1, until they're also as low as possible.

Now time to optimize the 4th timing, your TRAS, Remember that it (usually) needs to be around the sum of the previous three timings, so just keep that in mind
For example, if you got the first three timings down to 6-9-6, a good starting point for tRAS would be 6 + 9 + 6 = 21.

A small picture explaining what they do

Two sticks of RAM performing like one stick.. kind of?

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