If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below. |
|
|
|
Thread Tools | Display Modes |
#1
|
|||
|
|||
Motherboard memory voltage at boot, before SPD is read?
When a motherboard first turns on, what voltage is applied to the DIMMs,
just before the SPD profiles are read? Does the motherboard default to a high voltage first, like 1.65V for DDR3, and then lower it if the SPD specifies lower voltage, or does the motherboard start out at standard 1.50V and then adjust to the SPD voltage spec? |
#2
|
|||
|
|||
Motherboard memory voltage at boot, before SPD is read?
On Feb 21, 7:19 am, wrote:
When a motherboard first turns on, what voltage is applied to the DIMMs, just before the SPD profiles are read? Does the motherboard default to a high voltage first, like 1.65V for DDR3, and then lower it if the SPD specifies lower voltage, or does the motherboard start out at standard 1.50V and then adjust to the SPD voltage spec? The BIOS first reads the SPD EEPROM to configure the memory chip controller (MMC). Unless the MB has support provisions for auto- overclocking, implemented on some SPD tables, it's going to be a manual adjustment affair in either case to override and save them apart from BIOS defaults. |
#3
|
|||
|
|||
Motherboard memory voltage at boot, before SPD is read?
|
#4
|
|||
|
|||
Motherboard memory voltage at boot, before SPD is read?
On Feb 21, 11:05 am, Flasherly wrote:
On Feb 21, 7:19 am, wrote: When a motherboard first turns on, what voltage is applied to the DIMMs, just before the SPD profiles are read? Does the motherboard default to a high voltage first, like 1.65V for DDR3, and then lower it if the SPD specifies lower voltage, or does the motherboard start out at standard 1.50V and then adjust to the SPD voltage spec? You did say before a BIOS SPL read...eXcuSe me -- correction: The MB manufacturer meets compliance to JEDEC memory industry specifications, standards of memory class determination. Known as Stub Series Termination Logic voltage, its ratings as given under said standards will default either to 1.8V for DDR2 and 1.5V for DDR3. Since the pin- out slots are not interchangeable (by in large to negate a few extant, oddballed cross-dresser designs), accordingly, there's no apparent reason for a regulator stage to be pumping in 1.65V over JEDEC publications. As applicable, however, the "Tigers" known to inhabit the Pacific Rim well may deign during a course of implementation to supersede a stricter sense of compliance, to include naming conventions of a related complexity involving SSTL. Or so I suspect. How else could there be such pieces of crap manufactured under the namesake of a motherboard, such as BioStar? (....Duly bearing in mind, innovation, of course, is invariably the two-sided sword when cutting through lazy standards involving scribblers and dabblers, loose women, or the thinest slice of bread imaginable, nobody really is likely to notice amiss.) |
#5
|
|||
|
|||
Motherboard memory voltage at boot, before SPD is read?
On Thursday, February 21, 2013 11:32:00 AM UTC-7, Flasherly wrote:
The MB manufacturer meets compliance to JEDEC memory industry specifications, standards of memory class determination. Known as Stub Series Termination Logic voltage, its ratings as given under said standards will default either to 1.8V for DDR2 and 1.5V for DDR3. Since the pin-out slots are not interchangeable (by in large to negate a few extant, oddballed cross-dresser designs), accordingly, there's no apparent reason for a regulator stage to be pumping in 1.65V over JEDEC publications. As applicable, however, the "Tigers" known to inhabit the Pacific Rim well may deign during a course of implementation to supersede a stricter sense of compliance, to include naming conventions of a related complexity involving SSTL. Or so I suspect. How else could there be such pieces of crap manufactured under the namesake of a motherboard, such as BioStar? I thought manufacturers would start off their motherboards at higher than normal voltage to make it more likely they'd boot successfully with low quality DRAM. Most retail DRAM is made from chips that are either factory rejects or overclocked 30-100%. Here's some 2666 MHz Corsair made from 1333 MHz chips: http://www.xbitlabs.com/articles/mem...m_5.html#sect1 I have a BioStar G41-M7 motherboard with a minimum 1.95V voltage for its DDR2 memory. The BIOS also allows setting the voltage as high as 2.65V, or 0.3V above the absolute maximum for DDR2 chips, and I think an older BIOS allowed up to 2.75V. This is among the reasons BioStar is my 3rd least favorite brand of motherboard. |
#6
|
|||
|
|||
Motherboard memory voltage at boot, before SPD is read?
|
#7
|
|||
|
|||
Motherboard memory voltage at boot, before SPD is read?
On Feb 21, 6:27 pm, wrote:
On Thursday, February 21, 2013 11:32:00 AM UTC-7, Flasherly wrote: The MB manufacturer meets compliance to JEDEC memory industry specifications, standards of memory class determination. Known as Stub Series Termination Logic voltage, its ratings as given under said standards will default either to 1.8V for DDR2 and 1.5V for DDR3. Since the pin-out slots are not interchangeable (by in large to negate a few extant, oddballed cross-dresser designs), accordingly, there's no apparent reason for a regulator stage to be pumping in 1.65V over JEDEC publications. As applicable, however, the "Tigers" known to inhabit the Pacific Rim well may deign during a course of implementation to supersede a stricter sense of compliance, to include naming conventions of a related complexity involving SSTL. Or so I suspect. How else could there be such pieces of crap manufactured under the namesake of a motherboard, such as BioStar? I thought manufacturers would start off their motherboards at higher than normal voltage to make it more likely they'd boot successfully with low quality DRAM. Most retail DRAM is made from chips that are either factory rejects or overclocked 30-100%. Here's some 2666 MHz Corsair made from 1333 MHz chips: http://www.xbitlabs.com/articles/mem...-dominator-pla... I have a BioStar G41-M7 motherboard with a minimum 1.95V voltage for its DDR2 memory. The BIOS also allows setting the voltage as high as 2.65V, or 0.3V above the absolute maximum for DDR2 chips, and I think an older BIOS allowed up to 2.75V. This is among the reasons BioStar is my 3rd least favorite brand of motherboard. The thought occurred and I agree about giving it the extra juice. I never had a chance to get into them, one died on me within a year and the other wouldn't hold the BIOS settings. Although both were dirt cheap, so I guess I can afford to spit it out there once in awhile. God, 3rd-least...that's some system. Remind me not to go there anytime soon. Used to buy exclusively ABIT, if not ASUS, MSI is nothing spectacular but has treated me well over the years for a budget board (they're still viable imo, improved from a bad spell, with their newer offerings), whereas more of late I've also been looking over GigaByte without anything major to report -- used to know a pretty good code-breaker who would dimly swear by them over his coke- bottle glasses. My last ASUS failure was spectacularly horrific, along with some people I've met on realtime hardware chatlines working for them, I'm going along with a shift upwards on it's prices while QC is somewhat abated. JEDEC...who worries about that anymore when eying Ebay for surfeit parts. Mis-bought my last batch for DDR2 when I required 3. Hardly phased me with $12 and such sticks shipped free. I just get by on 1M with a crappy FireFox periodically gobbling it all up through a programming leak of cache into main memory (have a nifty restore crash&burn restore feature, tho, from back when FireFox was a real browser with real, not abandoned, extensions). |
#8
|
|||
|
|||
Motherboard memory voltage at boot, before SPD is read?
On Thu, 21 Feb 2013 18:57:49 -0500, Yousuf Khan
put finger to keyboard and composed: On 21/02/2013 7:19 AM, wrote: When a motherboard first turns on, what voltage is applied to the DIMMs, just before the SPD profiles are read? The DIMMs aren't activated until the SPD profiles are read. The motherboard first boots from its non-volatile EEPROM modules, not from its RAM. Yousuf Khan I notice that DIMMs provide a separate supply pin (VDDSPD) for the SPD serial EEPROM. - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#9
|
|||
|
|||
Motherboard memory voltage at boot, before SPD is read?
On 22/02/2013 4:49 AM, Franc Zabkar wrote:
On Thu, 21 Feb 2013 18:57:49 -0500, Yousuf Khan put finger to keyboard and composed: On 21/02/2013 7:19 AM, wrote: When a motherboard first turns on, what voltage is applied to the DIMMs, just before the SPD profiles are read? The DIMMs aren't activated until the SPD profiles are read. The motherboard first boots from its non-volatile EEPROM modules, not from its RAM. Yousuf Khan I notice that DIMMs provide a separate supply pin (VDDSPD) for the SPD serial EEPROM. Exactly, and chances are likely that this is a very standard power input voltage and current that probably never changes over generations. Yousuf Khan |
#10
|
|||
|
|||
Motherboard memory voltage at boot, before SPD is read?
Yousuf Khan wrote:
On 22/02/2013 4:49 AM, Franc Zabkar wrote: On Thu, 21 Feb 2013 18:57:49 -0500, Yousuf Khan put finger to keyboard and composed: On 21/02/2013 7:19 AM, wrote: When a motherboard first turns on, what voltage is applied to the DIMMs, just before the SPD profiles are read? The DIMMs aren't activated until the SPD profiles are read. The motherboard first boots from its non-volatile EEPROM modules, not from its RAM. Yousuf Khan I notice that DIMMs provide a separate supply pin (VDDSPD) for the SPD serial EEPROM. Exactly, and chances are likely that this is a very standard power input voltage and current that probably never changes over generations. Yousuf Khan The only incentive for it to change, is if the motherboard chipset can no longer tolerate such voltages (on SMBUS). As long as USB continues to be supported, things might not change (as USB uses a relatively high potential, on the legacy pins). Paul |
|
Thread Tools | |
Display Modes | |
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
Dell laptops vs Everest memory SPD report | Phil Schuman | Dell Computers | 0 | October 3rd 06 01:18 AM |
Relationship between AGP voltage setting in system bios and core/memory voltage? | Jack F. Twist | Overclocking | 1 | July 3rd 06 07:41 AM |
Is It Micron Technology Memory or? The Hunt for SPD Data? | W. Watson | Asus Motherboards | 4 | December 12th 04 01:52 AM |
Ti4400 or 4600, what's your agp voltage read? | GTX_SlotCar | Nvidia Videocards | 4 | September 26th 04 08:30 PM |
rewrite SPD EEPROM with motherboard ? | Harold | General | 1 | August 18th 03 01:00 AM |