Weird Max Memory Speed Reset Problem

LausDeo86

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I need some help with an overclocking issue I have. Here’s my PC specs:

Intel Core 2 Duo E6750 @ 2.66 GHz (333 MHz default FSB)
Mugen 2 CPU cooler, small northbridge fan
Radeon HD 4890
Motherboard: Gigabyte P35-DS3L, Rev. A2, BIOS Version: the latest F9C
4 GB of G.Skill RAM, 2 x 2 GB DDR2 1066 (PC28500), http://www.newegg.com/Product/Product.aspx?Item=N82E16820231166

I am overclocking for the first time. I tested my RAM (with manufactured stated timings and voltage set in BIOS) with Memtest86+ with each DIMM by themselves and together and all passed 12+ hours with no errors. I ran the prime95 blend test and it passed 11 hours with no errors. At full load under after 11 hours of the prime95 blend test, I checked my temps with Coretemp and my cores were at 42 degrees C and my northbridge at 48 degrees C. So I know my RAM is 100% good and my temps are good.

I overclocked my PC by upping my CPU Host Frequency from the default 333 MHz to 400 MHz. I set my System Memory Multiplier to 2.50 making my RAM run at 1000 MHz (my RAM max speed is 1066 MHz by default). I didn’t adjust voltages. I had my Static tRead value (aka tRD) to 8. It successfully booted into Windows with those settings and CPU-Z confirmed everything. I ran prime95 blend test and it passed. My core temps at full load were 46 degrees C and my northbridge at 49 degrees C. Perfect results.

THEN, the problem happened: I went back into BIOS and tried a higher FSB. After I rebooted my PC reverted back to stock or worse settings (333 MHZ CPU Frequency and my RAM at 633 MHz or some other low RAM speed) indicating it didn’t like my BIOS settings. Then I went back into BIOS and saw what appeared to be the issue: The max RAM speed listed under BIOS changed from 1066 MHz (which is the manufactured stated speed) to 800 MHz! What I mean by “max RAM speed” is that in my BIOS next to System Memory Multiplier (SPD) it will list the RAM max speed under SPD and then list an option for me to change it to what I want. A guide on my motherboard said, “This is the RAM SPD. Change this item so that the ‘Memory Frequency’ shown below the SPD is not exceeded. It is OK to be under the ‘Memory Frequency’ shown” (http://www.tomshardware.com/forum/245679-29-guide-overclocking-ds3l-updated-2008)

Well, before I changed my FSB above 400 MHz, the SPD max RAM speed always correctly said 1066 MHz. After I made the above change, it listed 800 MHz which is incorrect. Obviously with such a low RAM speed, I will always exceed the incorrectly listed 800 MHz RAM speed with anything above 400 MHz cpu frequency since my motherboard only lists 2x (aka 1:1) or higher memory multipliers. On top of that, another revealing issue showed itself. Before I did the above 400 MHz change, under “PC Health Status” in BIOS, my RAM voltage was always listed as 2.096V which is within the manufactured stated 2.0-2.1V range. After this weird 800 MHz max speed thing came, the “PC Health Status” listed my DDR2 voltage as 1.86V or something like that by default. That is weird.

After this weird change, I tried reverting back to my proven, working 400 MHz cpu, 1000 MHz RAM overclock and it won’t do it anymore. Adding more voltage to DDR2 to make it within range doesn’t fix it. Adding more cpu voltage doesn’t do anything. Nothing works. The only way I can get my RAM to run in 1066 MHz or near it is by reverting my FSB back to default 333 MHz.

Does anyone know how I can fix this problem? Anything I can try?

By the way, there is one possible explanation. A guide on overclocking my motherboard said, “IMPORTANT NOTE TO FUTURE P35-DS3L (and P35 DS3x /DS4x and other P35 chipset based) OWNERS: If you are planning on getting RAM natively higher than DDR2 800 be aware that there will be compatibility issues. Many users reports and my personal testing has shown that there is a very good chance you will run in to issues with RAM higher than DDR2 800, such as DDR2 1066. I recommend you get quality DDR2 800 RAM and run them at 1:1 ratio or overclock the RAM. This issue does not apply to DDR2 800 RAM that has been overclocked.”

This may be the issue. However, I have heard of another person on another forum overclocking on this motherboard with the same G.skill 1066 MHz RAM I have. Also, G.skill lists this motherboard as being compatible with it. Also, I have the latest bios which I hoped would fix this issue over the years. All of the aforementioned gave me hope I could overclock with 1066 RAM. However, should I just conclude the problem is the weird 1066 RAM incompatibility? Keep in mind I successfully overclocked to 400 MHz FSB running my RAM at 1000 MHz with prime95 passing at one point in time.

Any help is appreciated.

In case anyone wants to know, below are my relevant BIOS settings with my notes. I thoroughly went through overclocking guides for my mobo and am pretty sure I did everything right (at least the basics).

RGB: Auto
CPU Clock Ratio: 8x
CPU Host Clock Control: Enabled
CPU Host Frequency (MHz): 333 MHz is default; I change this for overclocking
PCI Express Frequency (MHz): 100 MHz
C.I.A.2: Disabled
Performance Enhance: Standard [Note: Manually Setting “Static tRead Value” which is tRD overrides the default “Performance Enhance” value anyway]
System Memory Multiplier: Set so I don’t exceed 1066 MHz. Note that this will need to be changed based on what my CPU Host Freq is.
System Voltage Control: Manual
DDR2 Overvoltage Control: Normal
PCI-E Overvoltage Control: Normal
FSB Overvoltage Control: Normal
(G)MCH Overvoltage Control: Normal
CPU Voltage Control: Normal
Static tRead Value: I set this at 8 for my overclock tests thus far which is conservative

The following two items are under “Advanced BIOS Features”:
CPI EIST Function [Speedstep]: Disabled
CPU Enhanced Halt (C1E): Not essential to disable for overclocking it seems; but some recommend disabling it. Hence, for now, I disabled it.
 

SpidersWeb

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I had a similar issue with an Asrock P45 board, once the FSB hits 400 the multipliers stop working properly. I can't be certain that's your issue unfortunately, but that was my first thought upon reading your post.

Gigabyte make good boards, just not sure if the P35 can do multis like that (I actually don't know).

Food for thought anyway. You could try increasing the MCH voltage (not too much).

If you can't get it working, you should be able to get your 1066 RAM to run at lower CAS settings when run in 800 mode. Mine managed 5-4-4-12 (down from 5-5-5-15 at 1066) at 800.
 

LausDeo86

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Thank you for your help.

I tried increasing the MCH voltage to no avail. I tried a few more tweaks, but still the same situation. What I can't get is how I could get 400 MHZ FSB with 1000 Mhz RAM earlier but now it won't work. Weird.

Unless someone can come up with a magical solution, I am tempted to think the problem is really that this mobo can't overclock 1066 Mhz RAM as that one guide said (see my original post) and hence I may have to burn more money on buying some crucial ballistix 800 Mhz RAM. At least I could sell my G.Skill's on ebay.

If you have any more advice I would appreciate it.
 

SpidersWeb

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1066 RAM is just factory overclocked 800. So you shouldn't need to sell the 1066 G-Skill's (unless there is something specific about the Crucial you need).

If it's CAS5 1066, you should be able to run it at 800 using CAS4 or almost CAS4 timings as well as a lower voltage. So you shouldn't need to sell your RAM to get the same performance as high spec 800.

Only downside is manually doing your memory timings can be painful, change one, reboot, change next, reboot, etc etc etc I still need to do mine, but in all honesty, the difference is so un-noticeable outside benchmarks, I haven't been bothered.
 

LausDeo86

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Thanks. The only problem is that I think my 1066 RAM is making it so that I can't increase my cpu FSB due to the 1066 overclocking RAM glitch the people at the forum were talking about. I want my CPU FSB to increase along with my RAM.
 

SpidersWeb

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Your BIOS/motherboard sets the RAM frequency, the 1066 just means your RAM is rated to run up to that speed without problems (not that is HAS to run at that speed).

Just set the DRAM Multiplier manually to 2.00 (on mine it's 2.00D or 400 x 2).

On my Asrock I did this, ran a 460 FSB, so the RAM was running at 920Mhz (DDR2-920). On my new Gigabyte I use the same setting, but threw the FSB speed up to 533Mhz (so now the RAM runs natively at 1066Mhz).

Edit: I don't recommend a 533 FSB, it makes the northbridge hotter than hell, I got a Xigmatech heatpipe cooler to keep it happy, and installing aftermarket generic chipset coolers is not a happy happy funtime :(
 

LausDeo86

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I decided to order some crucial ballistix RAM to see if it will work better. If not, I can return them.
I have a northbridge fan - I wonder if it will keep my NB cool enough with a FSB of 533 Mhz or higher.

What is considered a max okay temp for northbridge?
 
you should really be overclocking with a 1:1 ram ratio - best stability, and make sure you give your high spec ram enough v's - i usually give em atleast 0.1v extra, and make sure your timings are correct (set to auto but make sure in CPUz that its actually running the way it should)

Chipsets do run hot because they are usually pasivly cooled - a bit of airflow is usually all it needs

BTW E6xxx series cpus usually are harsh to get past the FSB1600 mark and ~3.5ghz core clock - check what others have been able to get.
 

LausDeo86

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I bought some Crucial Ballistix DDR2 800 (PC2 6400) 2x2 GB RAM dimms (BL2KIT25664AA80A) and they checked good with Memtest86+.

I proceeded to overclock and indeed the problem is solved! Truly I think that what the overclocking guide for the GA-P35-DS3L mobo said is true: You cannot overclock 1066 MHz RAM for whatever reason and the suggested route is to just use some good overclockable 800 MHz rated RAM and overclock it. (You can still achieve 1066 MHz anyway with a good pair of 800 MHz RAM). I'm selling my G.Skills.

Thanks for all your help and advice. So far I have my PC running at 420 Mhz FSB and 3.36 Ghz with 5-5-5-15 timings. It was stable under Prime95 indefinitely except one core failed after 8 hours, 23 minutes. Oh well. I am thinking of loosening my timings more and pushing my FSB higher and see how things go.