Memory Speed reported by BIOS

  • Thread starter Thread starter Grinder
  • Start date Start date
Grinder said:
I've recently bought and configured a new mainboard:

http://www.asrock.com/mb/overview.asp?Model=775Dual-VSTA

The board takes DDR2 667/533. Ive purchased and installed two 1GB
sticks of 667, which the board sees. The BIOS, however, reports it as
DDRII-533. As far as I can see there is no configuration option in the
BIOS.

Why would it report a slower speed for the RAM?

Here's the RAM I bought:

http://www.newegg.com/product/product.asp?item=N82E16820141210
Click to expand...
In the BIOS check the Advanced -page/chipset configuration for the DRAM
Frequency item.Where's it set.
 
In the BIOS check the Advanced -page/chipset configuration for the DRAM
Frequency item.Where's it set.
Click to expand...

Got it--thanks. Odd, though, that the field has an "Auto" setting but
could not determine the RAM's speed. I wonder what "Auto" does?
 
Why would it report a slower speed for the RAM?
Got it--thanks. Odd, though, that the field has an "Auto" setting but
could not determine the RAM's speed. I wonder what "Auto" does?
Click to expand...

It reads that little chip in the corner of the memory stick. The
manufacturer is supposed to put the timings for the memory in that small
eprom.
 
I've recently bought and configured a new mainboard:

http://www.asrock.com/mb/overview.asp?Model=775Dual-VSTA

The board takes DDR2 667/533. Ive purchased and installed two 1GB
sticks of 667, which the board sees. The BIOS, however, reports it as
DDRII-533. As far as I can see there is no configuration option in the
BIOS.

Why would it report a slower speed for the RAM?
Click to expand...

Because a memory spec does not mean "run it at this speed",
it means "this is the fastest it's guaranteed to run
stable".

It will report whatever speed it is running it at, which is
determined by the bios, either a default speed or one
changed by user intervention, reading an SPD table off the
memory EPROM, or a bios preset to run at either the same
clock rate as the CPU or +33 mode if the CPU FSB is that far
below what the chipset memory bus is rated to run stabily.

Here's the RAM I bought:

http://www.newegg.com/product/product.asp?item=N82E16820141210
Click to expand...

Odd, though, that the field has an "Auto" setting but
could not determine the RAM's speed. I wonder what "Auto" does?
Click to expand...

I wonder what CPU you have, what it's spec'd FSB rate is.
You might Google for "CPU-Z", run it, and compare the two
tabs in it, one tab for present speed of the memory and one
for the read SPD value.

You could always try manually setting the memory to the
speed (and timings spec'd for it, 4,4,4,12) and see if
that's stable (run memtest86+ for several hours to be sure
it's stable before booting the OS to avoid potential file
corruption), and if it isn't stable, adjust down the bus
speed, or higher timings, or some combination thereof until
you hit a stable zone with a bit of margin.
 
Grinder said:
Pen wrote
Click to expand...
Got it--thanks. Odd, though, that the field has an "Auto" setting but
could not determine the RAM's speed. I wonder what "Auto" does?
Click to expand...

Basically uses the data from the spd on the stick.

See what one of the utes that displays the spd data says about the spd data.
 
kony said:
I wonder what CPU you have, what it's spec'd FSB rate is.
Click to expand...

http://www.newegg.com/Product/Product.asp?Item=N82E16819116254

It's supposed to have an 800 MHz FSB.
You might Google for "CPU-Z", run it, and compare the two
tabs in it, one tab for present speed of the memory and one
for the read SPD value.
Click to expand...

The "Timings" panel on the "Memory" tab has a lot of blank and disabled
entries, including "Frequency." On the "SPD" tab, "Max Bandwidth"
reports PC2-5300 (333 MHz).
 
Grinder said:
http://www.newegg.com/Product/Product.asp?Item=N82E16819116254

It's supposed to have an 800 MHz FSB.


The "Timings" panel on the "Memory" tab has a lot of blank and disabled
entries, including "Frequency." On the "SPD" tab, "Max Bandwidth"
reports PC2-5300 (333 MHz).
Click to expand...

In terms of how a motherboard responds, it depends on the chipset.
For example, if the chipset used on the motherboard is from Intel,
then you can download the Intel Northbridge datasheet.

In the case of some Intel chipsets, there is one entry in the
datasheet that says that DDR2-667 at a certain CAS is not supported.
What seems to happen, is the motherboard manufacturers run the RAM
at DDR2-533, if that situation arises. Many users have managed to
manually set up their systems, at the "Intel disallowed" value and
it works fine. The Intel datasheet does not go into details as to
why that info is included, but the BIOS designers seem to partially
honor the Intel statement, by downclocking if the user selects
"Auto" or "By SPD".

For example, in the Intel 945 datasheet, it says (page 24):
ftp://download.intel.com/design/chipsets/datashts/30750203.pdf

"DDR2-667 4-4-4 is Not supported"

I only mention that, as a potential way of explaining the quirk.

Paul
 
http://www.newegg.com/product/product.asp?item=N82E16820141210

Something I've noticed about this memory: Newegg lists the Speed
(frequency) as 667, and the timings as 4-4-4-12. It turns out, though,
that the 4-4-4-12 timings listed in the SPD match up to a frequency of
533. Isn't newegg misrepresenting the memory with their mismatched specs?
Click to expand...


I doubt it, you wouldn't think all those newegg users would
rate it so well if it were, but admittedly I didn't read the
user reviews.

There are several bios updates for your board that address
memory. Until I saw that they had dual downloads for
Windows & DOS, I'd thought it must be the buggiest bios (or
best patching attempt ever) in recent history, but there are
several, you might try a newer bios if you don't have at
least version 1.8. On the other hand, if it was too
instable before 1.8 then they could've even chose to make it
downclock the memory. IMO, getting the newer bios and
seeing how it goes, then trying a manual adjustment is the
best attempt... if you're willing to spend the time testing
the resultant stability thoroughly.
 
Grinder said:
http://www.newegg.com/product/product.asp?item=N82E16820141210

Something I've noticed about this memory: Newegg lists the Speed
(frequency) as 667, and the timings as 4-4-4-12. It turns out, though,
that the 4-4-4-12 timings listed in the SPD match up to a frequency of
533. Isn't newegg misrepresenting the memory with their mismatched specs?
Click to expand...

No because the manufacturer states that this RAM is good for 667MHz speed
with latencies of 4-4-4-12 with a test voltage of 2.0V.
These are settings (including the voltage) that would have to be set
manually in the BIOS.
 
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