P965 "limitations" ?

imported_bc

Junior Member
Aug 24, 2006
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Looking at Intel's datasheet for the P965, it seems this chipset does not officialy support 1GB DDR800 modules. Could this be the reason for so many people having issues with the P965 boards ? Do the 512MB modules work better ?

Intel has also updated the P965 to C2 stepping (see Product Change Notification 106486 - 00). Do people with issues have the C1 or C2 stepping ?

Last, I was hoping t build a conroe overclocked rig with cheap ram, but it seems the P965 does not have memory dividers below 1:1 allowing high FSB with low RAM clock. I could not find any info in the datasheet on divider settings; anyone know ?
 

imported_Husky55

Senior member
Aug 15, 2004
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@bc

Thanks for the link.

1) There is no MB with 965P C2 stepping on the market at this time. The last I heard was C2 stepping chipset will ship on 9/17/2006 to MB manufacturers. Since NOBODY advertises C stepping of chipsets it's a hit or miss thing even after C2 was released. Eventually the inventory of C1 will clear up.

2) Intel did not specify the changes of C2 vs C1 except generalities i.e. minor changes etc...

3) I am not clear on the 965P not officially supporting 1GB DDR2 800 technology statement. There are numerous reports by web sites and end users of successful use of DDR2 800 1 GB sticks. There are plenty of reports of problems with different brands of MBs and memory manufacturers. Anandtech MB forums had a few reports on this.

4) AMD MB uses memory dividers ( I run an OC AMD system), Intel uses memory multipliers lingo to achieve essentially the same thing for OCers.
Again Anandtech reports of memory DDR2 Conroe testing will give you examples.

Frankly MBs, i.e. chipsets, compatibility and stability give me pause of building my next Conroe system. Read the comments on Asus and Gigabytes MBs raid problems relating to SATA and PATA drives, in addition to the memory and CPU non boot issues (there are workarounds).

:)

 

GuitarDaddy

Lifer
Nov 9, 2004
11,465
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I saw a post indicating that it wasn't possible to install OS on a raid array on the P5B vanilla, OS must be installed on a single drive.

Is this a P965 chipset limitation, or is it specific to that board only?


I am also curious about the mem ratio's, is 1:1 the lowest ratio available?
If true anything less than DDR2-800 or DDR2-1000 ram will severly limit overclocking on the lower clocked chips
 

slacker164

Junior Member
Aug 24, 2006
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Watch the difference between ?B? and ?b.? The spec sheet says 1Gb RAM is not supported; that?s 1Gbit and refers to the density of the individual chips. 1GByte RAM sticks use 512Mbit density chips and should be fully supported. It?s 2GB on a single stick that?s not (officially) supported. 512Mbit = 64MByte chips x 16 = 1GByte stick; 1Gbit = 128MByte chips x 16 = 2GByte stick. And yes? it can be confusing.
 

imported_Husky55

Senior member
Aug 15, 2004
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Originally posted by: slacker164
Watch the difference between ?B? and ?b.? The spec sheet says 1Gb RAM is not supported; that?s 1Gbit and refers to the density of the individual chips. 1GByte RAM sticks use 512Mbit density chips and should be fully supported. It?s 2GB on a single stick that?s not (officially) supported. 512Mbit = 64MByte chips x 16 = 1GByte stick; 1Gbit = 128MByte chips x 16 = 2GByte stick. And yes? it can be confusing.


Not bad slacker164!!! I think that makes sense.

@GuitarDaddy,

I am still running the Rightmark CPU Clock/Power Utility. Works great!!!

The 1:1 refers to the FSB (In MT/s or Megatransfers/sec), in this core 2 duo case, it would be 1066MT/s and the memory speed, in this case it would be 266MHz X 4=1066

When you use better memory, for instance DDR2-667 your ratio would be 4:5 or 1.25 multiplier, so your CPU speed would be faster but your MT/sec or FSB remains the same at 1066.

Of course if you buy DDR2-800 then you can do more!!!


:)
 

imported_bc

Junior Member
Aug 24, 2006
5
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@slacker164: thanks for clearing up the confusion!

@Husky55: the main performance gain come from overclocking the processor, and the RAM price becomes a limiting factor to reaching high FSB unless the FSB:RAM ratio can be lower than 1:1. The 975x supports 4:3, it would be a big drawback in terms of overclocked platform price if the P965 cannot be programmed to less than 1:1.

Concerning the C2 stepping, here's what Intel says it has fixed <quote> MCH ME ROM Initialization Hang; P965 Express Chipset Platforms Intermittently Lockup after Start\Shutdown initiated from OS or from Power Button </quote>
Sounds familiar with stuff on various forums, doesn't it?
 

imported_Husky55

Senior member
Aug 15, 2004
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Originally posted by: bc
@slacker164: thanks for clearing up the confusion!

@Husky55: the main performance gain come from overclocking the processor, and the RAM price becomes a limiting factor to reaching high FSB unless the FSB:RAM ratio can be lower than 1:1. The 975x supports 4:3, it would be a big drawback in terms of overclocked platform price if the P965 cannot be programmed to less than 1:1.

Concerning the C2 stepping, here's what Intel says it has fixed <quote> MCH ME ROM Initialization Hang; P965 Express Chipset Platforms Intermittently Lockup after Start\Shutdown initiated from OS or from Power Button </quote>
Sounds familiar with stuff on various forums, doesn't it?


@bc

You can run DDR533 as DDR667 and try to get the maximum RAM speed your memory is capable of doing.

 

imported_bc

Junior Member
Aug 24, 2006
5
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@Husky55: if I were stuck with FSB:RAM @1:1, I would want to do the opposite: get DDR800 and set it to DDR533 [default conroe FSB is 1066], in order to be able to ramp up FSB as high as it would go to overclock the CPU to the max without hitting a RAM ceiling. Ideally what I would like to do is buy cheapo DDR400 RAM, set FSB:RAM @2:1 and try to ramp FSB to get the best CPU overclock. RAM hardly matters, it's been documented in a dedicated Anandtech article.

@GuitarDaddy: doesn't the P5B vanilla have the ICH8 rather than the ICH8R ? R stands for raid.
 

Auric

Diamond Member
Oct 11, 1999
9,596
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In addition to the defects admitted by Intel, Fast Memory Access is reportedly not functioning correctly with C-1 and DDR2 800, at least.