NEED help with 975XBX2 and Corsair XMS PC2 8500

[hexeis]

Hi all,

I just recently bought this combination. I don't think the board supports 1066Mhz. If this is the case what are the settings required to have the fastest 800Mhz DDR2 setup with this combination?

Am running a

BOX975XBX2KR mobo
Intel Core 2 Duo E6700
ATI X1950Pro 256MB

I'm somewhat noobish in the DDR2 clocking methods.

Thanks all.

[Apoptosis]

It's tough to get 1066MHz on the 975x chipset... Since everything is linked it's harder than say a 680i board...

What are you overclocking your E6700 to? What voltages are you running everything at?

[hexeis]

Do you think it's worth it to go through the trouble of returning this mobo and getting a 680i ?

The problem is that Intel's BIOS is unlike what I"m used to and I've had a laptop for the past year so I'm rusty tweaking desktops.

Currently my settings are

200 Mhz
667Mhz
4
4
4
12

and it results in a 3:5 888Mhz DDR

I don't know how to take it higher with this board.

[hexeis]

Do you think it's worth it to go through the trouble of returning this mobo and getting a 680i ?

The problem is that Intel's BIOS is unlike what I"m used to and I've had a laptop for the past year so I'm rusty tweaking desktops.

Currently my settings are

200 Mhz
667Mhz
4
4
4
12

and it results in a 3:5 888Mhz DDR

I don't know how to take it higher with this board.

voltage at 2.2V

[Apoptosis]

Do you think it's worth it to go through the trouble of returning this mobo and getting a 680i ?

The problem is that Intel's BIOS is unlike what I"m used to and I've had a laptop for the past year so I'm rusty tweaking desktops.

Currently my settings are

200 Mhz
667Mhz
4
4
4
12

and it results in a 3:5 888Mhz DDR

I don't know how to take it higher with this board.

Hexeis,

To be honest if you want a 680i WickedLD9 here on the forums is getting ready to sell his BFG Tech 680i to buy a 975XBX2 for his personal Kentsfield system... maybe you guys can work out a swap deal if you really wanted to go that route. Brian and I both have 680i and 975XBX2 boards and after using both we both prefer the 975XBX2 as it has better memory performance and is more quad-core friendly.

I'm getting ready to post an article that shows the differences between 800MHz - 1250Mhz memory on the 680i motherboard and the differences are hardly anything...

As for the 975XBX2 change the memory strap to 800Mhz.

[hexeis]

jeeez one year out of the desktop world and i turn into a huge noob

"memory strap"

what is that?

[hexeis]

These are my current settings. What do you guys think? Can I do better?

[Apoptosis]

try changing the memory speed -- increase it from 667 to 800 in the BIOS... By doing this it will change the memory divider and give you a higher frequency on your memory.

Here is a picture I took of it at 667...

[hexeis]

try changing the memory speed -- increase it from 667 to 800 in the BIOS... By doing this it will change the memory divider and give you a higher frequency on your memory.

Here is a picture I took of it at 667...

We have different BIOS's I'll come back with a screenshot of mine.

[hexeis]

So here is what the memory settings look like in my BIOS



What's confusing is that there's a reference frequency and a memory frequency. I don't know the difference between the two.

This is the reference frequency and it's options.



Then finally, here are the options under memory frequency.



What is optimal here? Also, bear in mind that these settings are what I currently have for the results you saw in the earlier post.

Thanks for your help peeps!

[kenc51]

"Reference freq" is the NB strap, when you run the ram on the 1066 divider the chipset will use loose timings to allow for the high frequency, lower dividers give lower (chipset) latencies (more perormance). Intel has allowed people to modify this internal chipset timings by forcing this "strap"
The lower the reference frequency is the lower the timings, ie. better performance. you should use the 800MHz setting here as it gives the best pefomance and still allows for high memory overclocks.

[Apoptosis]

yup... try setting the memory frequency to 800MHz, but if it doesn't work watch the timings as 4-4-4-12 is agressive.

[hexeis]

yup... try setting the memory frequency to 800MHz, but if it doesn't work watch the timings as 4-4-4-12 is agressive.

I just did that and the performance is actually slower. I saved SiSoft benches on both configs.

[Apoptosis]

hexeis,

Great, it sounds like you are on the right path... Get out a notepad and use Sandra to find the setting that gives you the most bandwidth. I personally run 3-3-3-9 timings at 800MHz as they give me the best bandwidth.

Basically set aside a couple hours and find the best settings and use CPU-Z to record the frequency and timings.

[hexeis]

So does anyone know how far you can overclock ram to on the XBX2?

Here is my SiSoft report:

SiSoftware Sandra

Benchmark Results
RAM Bandwidth Int Buff'd iSSE2 : 5763 MB/s
RAM Bandwidth Float Buff'd iSSE2 : 5770 MB/s
Results Interpretation : Higher index values are better.

Int Buff'd iSSE2 (Integer STREAM) Results Breakdown
Assignment : 5576MB/s
Scaling : 5559MB/s
Addition : 5971MB/s
Triad : 5946MB/s
Data Item Size : 16 byte(s)
Buffering Used : Yes
Offset Displacement Used : Yes
Bandwidth Efficiency : 67% (estimated)

Float Buff'd iSSE2 (Float STREAM) Results Breakdown
Assignment : 5598MB/s
Scaling : 5564MB/s
Addition : 5965MB/s
Triad : 5955MB/s
Data Item Size : 16 byte(s)
Buffering Used : Yes
Offset Displacement Used : Yes
Bandwidth Efficiency : 68% (estimated)

Performance Test Status
Run ID : AVALANCHE on Saturday, February 03, 2007 at 6:14:35 PM
Memory Used by Test : 512MB
NUMA Support : No
SMP Test : No
Total Test Threads : 1
Multi-Core Test : Yes
SMT Test : No
Dynamic MP/MT Load Balance : No
Processor Affinity : P0C0T0
System Timer : 2.7GHz
Page Size : 4kB
Use Large Memory Pages : No

Features
SSE Technology : Yes
SSE2 Technology : Yes
SSE3 Technology : Yes
Supplemental SSE3 Technology : Yes
HTT - Hyper-Threading Technology : No

Chipset 1
Model : Intel Corporation 82975X Memory Controller Hub
Front Side Bus Speed : 4x 267MHz (1068MHz data rate)
Width : 64-bit
Maximum Bus Bandwidth : 8544MB/s (estimated)

Logical/Chipset 1 Memory Banks
Bank 0 : 512MB DDR2-SDRAM 4.0-4-4-12 (tCL-tRCD-tRP-tRAS) CR1
Bank 1 : 512MB DDR2-SDRAM 4.0-4-4-12 (tCL-tRCD-tRP-tRAS) CR1
Bank 4 : 512MB DDR2-SDRAM 4.0-4-4-12 (tCL-tRCD-tRP-tRAS) CR1
Bank 5 : 512MB DDR2-SDRAM 4.0-4-4-12 (tCL-tRCD-tRP-tRAS) CR1
Channels : 2
Speed : 4x 222MHz (888MHz data rate)
Width : 64-bit
Performance Acceleration Technology : Yes
Memory Controller in Processor : No
Maximum Memory Bus Bandwidth : 14208MB/s (estimated)

Performance Tips
Notice 5405 : System bandwidth appears FSB limited. Attempt to increase FSB.
Notice 5008 : To change benchmarks, click Options.
Notice 5004 : Synthetic benchmark. May not tally with 'real-life' performance.
Notice 5006 : Only compare the results with ones obtained using the same version!
Tip 2 : Double-click tip or press Enter while a tip is selected for more information about the tip.

Checkout the information in BOLD.

4x222Mhz (888Mhz data rate) This is my current memory speed. How is that 222Mhz generated?

this is with

reference frequency of 200Mhz
memory frequency of 667Mhz
4
4
4
12
2.2V

The big question is how do those numbers generate a 222Mhz memory clock?!? Remember CPU-Z is calling out a 444Mhz with these same settings - which is no surprise.

[kenc51]

It's DDR2 so you multiply it by four! It's usually quoted as either ~400MHz or ~800MHz, no-one really uses the "200MHz" speed except Sandra.
Go by what CPUZ says.
With that board your max will be ~1200MHz on the RAM, even then that's very high. You would need to increase the chipiset voltage to it's max or even volt=mod it.
I'd say 1100MHz is a reasonable limit for a 975 chipset board.
You should set the RAM to use the 800MHz divider and reference Freq, set the vdimm (ram voltage) to 2.1v and start increasing the FSB by ~5MHz at a time. Boot into windows and run some stress tests, like 2 instances SuperPi 32M, Orthos (blend test) and when you think it's stable, increase the FSB by another ~5MHz.
When things get unstable, add some more chipset voltage, it that doesn't help, add a little more vcore (cpu voltage)
If you use 2.2V or more on the RAM add a fan to blow air over them as they will get hot. Also the chipset heatsink will get hot after adding more voltage, so a fan there will help too.
Basically you need to watch your temps, and test everything methodically for stability. Keep a pen and piece of paper nearby to take notes on what settings work and don't.
It can be boring at first to do, this is why most people tend to only overclock a little, but if your carefull you should find you can add ALOT more performance if you have the patience..........
With alot of things in life, if you put the effort in, you should see the rewards!

[hexeis]

check this link out!

http://www.peakin.com/xbx2/calculator.html

[Apoptosis]

now that is damn sweet... great find

[seanriddle]

From experimentation, the ratios don't change when I select a ref freq of 333. I get the same ones (and therefore the same mem speeds) as 266. The measured RAM speed does decrease, probably from the greater latencies of the 1333 NB strap.

Sean

[hexeis]

has anyone used this hardware combination? do you guys think it's worth it? I haven't been able to reach higher than DDR 888 with 4-4-4-12