Memory confusion - P5WD2
in [Asus]
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From: DCIFRTHS on 22 Oct 2005 19:56 Hi, The chipset on this motherboard officially supports DDR2 667 as the fastest memory. Asus describes this motherboard as natively supporting DDR2 800. Can someone explain, if the memory controller supports up to 667, how the board natively supports the 800 speed? Additionally, if I plug in a DDR2 800 module that has the SPD set at 2.1V with timings of 4-4-4-12, will the board recognize this module, and overclock the memory bus to run it at those speeds, or will run it at slower speed by default? Thanks for any insight to this situation!
From: Paul on 22 Oct 2005 22:38 In article <JkA6f.1348$c%.952(a)trndny02>, "DCIFRTHS" <DCIFRTHS(a)nowhere.com> wrote: > Hi, > > The chipset on this motherboard officially supports DDR2 667 as the fastest > memory. Asus describes this motherboard as natively supporting DDR2 800. Can > someone explain, if the memory controller supports up to 667, how the board > natively supports the 800 speed? > > Additionally, if I plug in a DDR2 800 module that has the SPD set at 2.1V > with timings of 4-4-4-12, will the board recognize this module, and > overclock the memory bus to run it at those speeds, or will run it at slower > speed by default? > > Thanks for any insight to this situation! From the manual: ******* DRAM Frequency [Auto] Allows you to set the DDR operating frequency. Configuration options: [Auto] [DDR2-400MHz] [DDR2-533MHz] [DDR2-667MHz] [DDR2-800MHz] [DDR2-711MHz] [DDR2-889MHz] [DDR2-1067MHz] Available DRAM frequency options in various FSB settings FSB Configuration options Auto DDR2- DDR2- DDR2- DDR2- DDR2- DDR2- DDR2- 400 533 667 711* 800* 889* 1067* FSB 1066 ? ? ? ? ? ? ? ? FSB 800 ? ? ? ? ? FSB 533 ? ? ? * Provided for overclocking purpose only. ******* The SPD EEPROM chip on a DIMM, is only supposed to be programmed with JEDEC approved information. This aids compatibility, in that a BIOS only need know how to parse the expected JEDEC values. I cannot find a reference to what JEDEC currently approves, and if the max is still DDR2-667, then that is all you should be finding programmed into the SPD. AFAIK, for overclockable modules, it is up to the user to set the parameters to reach the maximum value. After all, you want the computer to be able to POST first, and then try overclocking it. If the computer failed to POST, because of some problem running at DDR2-800, you'd be pissed. Paul
From: DCIFRTHS on 23 Oct 2005 02:16 Paul, The information you provided to me confirms my original posting. Anything above DDR 667 is considered overclocking. The modules in question are Crucial Ballistix modules. The specs are here http://www.crucial.com/store/partspecs.Asp?IMODULE=BL2KIT12864AA804 I specifically asked Crucial what the SPD was programmed to, and they insisted (more than one rep confirmed this) that it was set to the timings listed in the link above (4-4-4-12). This seems rather strange to me. If anyone is using Ballistix modules and can confirm the part number they have, and what the SPD is programmed to, I would greatly appreciate it. I also searched for the standard JEDEC timings, but couldn't find them. Kingston and Corsair have some information, but they seem to differ on what the standard is. I am total agreement that the SPD should be set to JEDEC standards. "Paul" <nospam(a)needed.com> wrote in message news:nospam-2210052237550001(a)192.168.1.178... > In article <JkA6f.1348$c%.952(a)trndny02>, "DCIFRTHS" <DCIFRTHS(a)nowhere.com> > wrote: > >> Hi, >> >> The chipset on this motherboard officially supports DDR2 667 as the >> fastest >> memory. Asus describes this motherboard as natively supporting DDR2 800. >> Can >> someone explain, if the memory controller supports up to 667, how the >> board >> natively supports the 800 speed? >> >> Additionally, if I plug in a DDR2 800 module that has the SPD set at 2.1V >> with timings of 4-4-4-12, will the board recognize this module, and >> overclock the memory bus to run it at those speeds, or will run it at >> slower >> speed by default? >> >> Thanks for any insight to this situation! > > From the manual: > > ******* > DRAM Frequency [Auto] > > Allows you to set the DDR operating frequency. > > Configuration options: [Auto] [DDR2-400MHz] [DDR2-533MHz] > [DDR2-667MHz] [DDR2-800MHz] [DDR2-711MHz] [DDR2-889MHz] > [DDR2-1067MHz] > > Available DRAM frequency options in various FSB settings > > FSB Configuration options > Auto DDR2- DDR2- DDR2- DDR2- DDR2- DDR2- DDR2- > 400 533 667 711* 800* 889* 1067* > FSB 1066 ? ? ? ? ? ? ? ? > FSB 800 ? ? ? ? ? > FSB 533 ? ? ? > * Provided for overclocking purpose only. > ******* > > The SPD EEPROM chip on a DIMM, is only supposed to be programmed > with JEDEC approved information. This aids compatibility, in > that a BIOS only need know how to parse the expected JEDEC > values. I cannot find a reference to what JEDEC currently > approves, and if the max is still DDR2-667, then that is all > you should be finding programmed into the SPD. > > AFAIK, for overclockable modules, it is up to the user to set the > parameters to reach the maximum value. After all, you want the > computer to be able to POST first, and then try overclocking it. > If the computer failed to POST, because of some problem running > at DDR2-800, you'd be pissed. > > Paul
From: DCIFRTHS on 23 Oct 2005 02:31 Forgot to add that Crucial told me that there are no JEDEC timing standards for DDR2. They said it only specifies the voltage and frequency (MHz). Anyone know if this is true? "Paul" <nospam(a)needed.com> wrote in message news:nospam-2210052237550001(a)192.168.1.178... > In article <JkA6f.1348$c%.952(a)trndny02>, "DCIFRTHS" <DCIFRTHS(a)nowhere.com> > wrote: > >> Hi, >> >> The chipset on this motherboard officially supports DDR2 667 as the >> fastest >> memory. Asus describes this motherboard as natively supporting DDR2 800. >> Can >> someone explain, if the memory controller supports up to 667, how the >> board >> natively supports the 800 speed? >> >> Additionally, if I plug in a DDR2 800 module that has the SPD set at 2.1V >> with timings of 4-4-4-12, will the board recognize this module, and >> overclock the memory bus to run it at those speeds, or will run it at >> slower >> speed by default? >> >> Thanks for any insight to this situation! > > From the manual: > > ******* > DRAM Frequency [Auto] > > Allows you to set the DDR operating frequency. > > Configuration options: [Auto] [DDR2-400MHz] [DDR2-533MHz] > [DDR2-667MHz] [DDR2-800MHz] [DDR2-711MHz] [DDR2-889MHz] > [DDR2-1067MHz] > > Available DRAM frequency options in various FSB settings > > FSB Configuration options > Auto DDR2- DDR2- DDR2- DDR2- DDR2- DDR2- DDR2- > 400 533 667 711* 800* 889* 1067* > FSB 1066 ? ? ? ? ? ? ? ? > FSB 800 ? ? ? ? ? > FSB 533 ? ? ? > * Provided for overclocking purpose only. > ******* > > The SPD EEPROM chip on a DIMM, is only supposed to be programmed > with JEDEC approved information. This aids compatibility, in > that a BIOS only need know how to parse the expected JEDEC > values. I cannot find a reference to what JEDEC currently > approves, and if the max is still DDR2-667, then that is all > you should be finding programmed into the SPD. > > AFAIK, for overclockable modules, it is up to the user to set the > parameters to reach the maximum value. After all, you want the > computer to be able to POST first, and then try overclocking it. > If the computer failed to POST, because of some problem running > at DDR2-800, you'd be pissed. > > Paul
From: Paul on 23 Oct 2005 04:52 In article <7VF6f.3313$%A1.2424(a)trndny01>, "DCIFRTHS" <DCIFRTHS(a)nowhere.com> wrote: > Paul, > > The information you provided to me confirms my original posting. Anything > above DDR 667 is considered overclocking. > > The modules in question are Crucial Ballistix modules. The specs are here > http://www.crucial.com/store/partspecs.Asp?IMODULE=BL2KIT12864AA804 > > I specifically asked Crucial what the SPD was programmed to, and they > insisted (more than one rep confirmed this) that it was set to the timings > listed in the link above (4-4-4-12). This seems rather strange to me. If > anyone is using Ballistix modules and can confirm the part number they have, > and what the SPD is programmed to, I would greatly appreciate it. > > I also searched for the standard JEDEC timings, but couldn't find them. > Kingston and Corsair have some information, but they seem to differ on what > the standard is. I am total agreement that the SPD should be set to JEDEC > standards. I don't think this document is going to help matters - I was really surprised to find that JEDEC has put this in the free download catagory. PDF page 74 has some classifications for the memory - 800's come in 4's, 5's, and 6's , 667's in 4's and 5's, both 400's and 533's come in 3's and 4's. http://www.jedec.org/download/search/JESD79-2B.pdf I had to register to use the search engine, but if you are lucky, the document will download for you without further hassle. Now, let's review the situation on your motherboard again. Say that JEDEC is actually allowing DDR2-800, according to that Jan. 2005 document above. In the BIOS, Asus can still consider the use of the divider that gives DDR2-800, to be non-standard, which means even if the top timing in the SPD is for DDR2-800, the BIOS is still under no obligation to go there immediately. I just looked in the Intel 955X chipset datasheet, and DDR2-667 is considered to be the top speed. That could mean, that the dividers used to get the higher memory clocks are undocumented or unsupported by Intel. (I didn't read the whole doc. My past experience is, Intel is not completely honest about what dividers are available.) PDF page 20 has a strange statement. And there is no elaboration later. It says DDR2-667 4-4-4 is not supported ? I wonder what the hell that means. They don't make datasheets the way they used to... http://download.intel.com/design/chipsets/datashts/30682801.pdf I looked in the Crucial FAQ database and found this: http://www.crucial.com/kb/answer.asp?qid=4050 "The specs for your DDR2 Ballistix products have two values listed. One is a "validated" value, while the other is an "SPD" value. Why are these different? The memory timings listed as the validated values are the timings that we actually test our Ballistix products to. The timings listed as SPD settings are the values that are programmed into the module's SPD. Your system's BIOS will often use these values as the default for your memory settings. The timing values in the SPD are not set as aggressively as the ones used in our test flow because many systems are not capable of running at these tighter timing settings. By programming less aggressive values into the SPD, we are able to maximize the number of platforms that DDR2 Ballistix products will work with right out of the box. To operate at the published validated timing specifications, you may need to manually set these parameters in your BIOS. Consult your motherboard manufacturer's documentation for detailed information on how to change these settings." They said it better than I could :-) Paul > "Paul" <nospam(a)needed.com> wrote in message > news:nospam-2210052237550001(a)192.168.1.178... > > In article <JkA6f.1348$c%.952(a)trndny02>, "DCIFRTHS" <DCIFRTHS(a)nowhere.com> > > wrote: > > > >> Hi, > >> > >> The chipset on this motherboard officially supports DDR2 667 as the > >> fastest > >> memory. Asus describes this motherboard as natively supporting DDR2 800. > >> Can > >> someone explain, if the memory controller supports up to 667, how the > >> board > >> natively supports the 800 speed? > >> > >> Additionally, if I plug in a DDR2 800 module that has the SPD set at 2.1V > >> with timings of 4-4-4-12, will the board recognize this module, and > >> overclock the memory bus to run it at those speeds, or will run it at > >> slower > >> speed by default? > >> > >> Thanks for any insight to this situation! > > > > From the manual: > > > > ******* > > DRAM Frequency [Auto] > > > > Allows you to set the DDR operating frequency. > > > > Configuration options: [Auto] [DDR2-400MHz] [DDR2-533MHz] > > [DDR2-667MHz] [DDR2-800MHz] [DDR2-711MHz] [DDR2-889MHz] > > [DDR2-1067MHz] > > > > Available DRAM frequency options in various FSB settings > > > > FSB Configuration options > > Auto DDR2- DDR2- DDR2- DDR2- DDR2- DDR2- DDR2- > > 400 533 667 711* 800* 889* 1067* > > FSB 1066 ? ? ? ? ? ? ? ? > > FSB 800 ? ? ? ? ? > > FSB 533 ? ? ? > > * Provided for overclocking purpose only. > > ******* > > > > The SPD EEPROM chip on a DIMM, is only supposed to be programmed > > with JEDEC approved information. This aids compatibility, in > > that a BIOS only need know how to parse the expected JEDEC > > values. I cannot find a reference to what JEDEC currently > > approves, and if the max is still DDR2-667, then that is all > > you should be finding programmed into the SPD. > > > > AFAIK, for overclockable modules, it is up to the user to set the > > parameters to reach the maximum value. After all, you want the > > computer to be able to POST first, and then try overclocking it. > > If the computer failed to POST, because of some problem running > > at DDR2-800, you'd be pissed. > > > > Paul
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