Bios Only Reports 1/2 the RAM Installed

[PeteF]

I'm attempting to revive an old 400MHZ PII computer with ASUS Mobo model
P2B-F to run Linux Freespire, so I need to increase the RAM to about 512mb
to get good performance.

My Asus P2B-F manual says I need SDRAM PC100, unbuffered 3.3v
I have 2 RAM sticks in Slot1 and Slot 2 as follows and this configuration
works perfectly.

Slot1: Value RAM 256MB, PC133, 9 chips on 2 sides.
Slot1: Corsair RAM, 64MB PC100, 9 chips on 1 side.
Slot3:
Slot4:

I checked the Bios settings..
* Check Data Integrity.... ECC Disabled
* CPU Level 2 cache ECC check.. Disabled.
* SDRAM configuration... By SPD

I purchased 2 sticks of new RAM, but when I removed all the
old RAM and installed the 2 new sticks the Bios only reports
262MB RAM when it should be 512MB.

Slot1: PNY RAM, 256 MB, PC133, 8 chips on one side.
Slot2: PNY RAM, 256 MB, PC133, 8 chips on one side.
Slot3:
Slot4:

If I only install one of the PNY RAM sticks the bios report 131MB.
I tried each one separately with same result. I also verified in another
computer that these RAM sticks are indeed good.

I realize that 8 chips means no ECC, but I can't figure
out why it is only reporting about half the MBs.
It's looking like the bios won't properly recognize RAM chips with only 8 chips.

* Why is it only reporting about half the RAM installed?

* Is there anything I can do in the BIOS to make it work properly?

* Would upgrading the BIOS do any good?
(Currenly have Award Bios v4.5PG from 1998)
There is a Version 1011 2002/08/05 update for this Mobo online.

* What specs do I need to to comply with when buying RAM for this mother board?

---pete---

[Seth]

Pete,

I was checking out the mobo's manual (http://www.solorb.com/gsale/p2bf-103.pdf#search=%22Asus%20P2B-F%22).

That memory you have should be fine as long as ECC is disabled (which you've done).

Did you try the other slots?

Also, on page 17 of the manual. It states that if pc 100 isn't being used, then change the CPU bus frequency to 66mhz to ensure system stability. Now, you wouldn't think that would have any affect on the amount of ram being reported, but you never know....perhaps the incorrect bus frequency is trying to compensate by ignoring some of the ram.

[PeteF]

Did you try the other slots?

Also, on page 17 of the manual. It states that if pc 100 isn't being used, then change the CPU bus frequency to 66mhz to ensure system stability.

Yes, tried other slots.

I'm pretty sure in qute above that the manual is assuming that
if PC100 isn't being used, then you are using something less
than PC100. In 1998, when the manual was written,PC133
might not have existed yet.

One more clue...
I was researching RAM on eBay and one vendor selling
RAM had 256MB SDRAM PC133, and he stated it was
"True" PC133 and NOT COMPATIBLE WITH PC100.
Now that struck me as odd because normally you can
go higher on the RAM stick PCxxx spec ref to what
the motherboard requires. In other words, PC100
or higher will work on mobo speced for PC100.

It seems more related to the number of chips on
the ram stick where 9 chips (per side) are detected
properly but 8 chips (per side) are not. This is
also odd becasue 8 chips just means no ECC and I
have that disabled in the BIOS.

---pete---

[Seth]

Yes, you're right on that assumption. I was grasping at straws without taking into account the age of the board.

That's a popular board. I would investigate a bios update that addresses such an issue.

[Seth]

I just checked the Asus site. There is no bios update of relevance.

[Seth]

Funny though, the manual mentions the 8 chip sticks, but it doesn't say anything about them not being read properly...just a not about ECC.

[PeteF]

I just checked the Asus site. There is no bios update of relevance.

I purchased the mobo in 1998 and the Bios upgrades on
the Asus website are dated 2002. ---pete---

[Seth]

Ya I saw that, but the release notes don't mention a ram fix. Won't hurt to try though, as they don't always list the fixes.

[PeteF]

Ya I saw that, but the release notes don't mention a ram fix. Won't hurt to try though, as they don't always list the fixes.

Oh, I missed that. I didn't see the release notes.
I tried posting on the Asus Motherboard Forum, but there seems to
be something wrong with their server this weekend. ---pete---

[mylanta]

I have seen a lot of old boards that will not see Pc 133 that is supposedly compatible to Pc 100.

[PeteF]

I have seen a lot of old boards that will not see Pc 133 that is supposedly compatible to Pc 100.

Ok, so maybe it's a memory vendor to vendor issue becasue this
Mobo does work with Value RAM PC133, but not PNY RAM PC133.

Perhaps a call to a memory vendor will clear this up.

So far it seems the 9 chips (1 side or 2 sides), is most
compatible with this particual Asus Mobo.

Thanks for the info!

---pete---

[dbarrow]

http://www.abxzone.com/forums/
Search P2B-F returned quite a few threads.
I didn't read them but maybe your anwser lies in there.

Some Asus mobos were very picky about ram, how much, chips per side, and in what slots.
This is now very old information so it may be difficult to pin that down.

Is it 4 slot?
Try other slots, sometimes must be 1+3 or 2+4 rather than 1+2, 3+4.

Slots can go bad... CUSL2 dropped one slot after many intermittant problems. Had to put a single 512 in slot 1 and take out 256x2

[PeteF]

Some Asus mobos were very picky about ram, how much, chips per side, and in what slots.
This is now very old information so it may be difficult to pin that down.

Is it 4 slot?
Try other slots, sometimes must be 1+3 or 2+4 rather than 1+2, 3+4.


I tried all kinds of combos but the result was always the
same with the PNY RAM. It helps a lot to know this is a common
problem. My best bet is to stick with 9 chip types and brands
that worked in the past.

I have a post on the Asus Forum but no replies yet out
of 12 views.

Thanks for the info!

---pete---

[PeteF]

Thanks all who responded!
I did not receive any answers at the Asus Forum but crucial.com has
an excellent configurator that has memory list for my exact Asus mobo
model P2B-F. The memory they have is more expensive than I'd expect
($81-$93 for ECC 256mb). Below is what they have to say about that.
---pete---

Source:
http://www.crucial.com/store/listparts.asp?mfr=&model=P2B-F&tabid=AM

Important information about your computer
Your system only supports modules made with a specific type of chips.
While you might find what appears to be the exact same memory for a
lower price elsewhere, the cheaper memory might not work in your system.

The Crucial Memory Selector only selects memory that is 100% guaranteed
compatible with your system or we'll give you your money back! Learn more
about chip density, memory prices, and compatibility here. (see full details
listed below)

Source:
http://www.crucial.com/library/128Mb_vs_256Mb.asp

Compatibility. It's Crucial.
Chip density, compatibility, and pricing
At Crucial, we strive to keep our memory prices as low as possible. But there are times you will find what appears to be the exact same memory from one of our competitors for a lower price than we are offering. Why is this? Key word: appears!

So why are there price differences among memory modules that appear to have the exact same specifications? There is a good reason for the higher prices: memory density migration and how it relates to compatibility with different computers. Let's explain.

When computer manufacturers design and build new computers, they attempt to build in support for all DRAM chip densities that are available at the time. Years ago, when the first PC100 systems were released, the only DRAM densities available were 16Mb chips and 64Mb chips. However, 128Mb chips were in the design phase, so computer manufacturers built support for this higher memory density into their systems.

Memory manufacturers are constantly striving to reduce their cost-per-bit while they migrate production to chips with greater densities. Today, we are capable of producing chips with densities of 256Mb and 512Mb. Crucial's parent company, Micron, is in a leading position in providing a 1 Gb chip. As manufacturers get more density (storage) per chip and migrate to newer processes, the production cost per megabit decreases.

The market price of memory chips is dictated by supply and demand. As demand increases for a higher density chip, the demand for older, lower density chips usually declines. Manufacturers typically shift their production accordingly. If the supply of the lower density chips decreases faster than demand, the market price per bit on these chips will remain high in comparison to the newer, higher density chips. This is what is occurring now with pricing for 128Mb SDRAM chips relative to 256Mb SDRAM chips.

The problem is that a great many older systems in use today often cannot support the newer, higher density, less expensive chips. A computer's chipset can only support the memory technology it was designed with, and the majority of systems out there only support lower density modules.

To an unsuspecting consumer who doesn't know about chip density and compatibility, the lower price is understandably more appealing. Especially when the specifications appear to be identical. But there's nothing more annoying than opening up your machine and installing your new memory only to find that it doesn't work with your system. The anticipation of better performance quickly turns to frustration as you face the task of uninstalling the memory, packaging it up, and sending it back. At this point, your best bet is to cross your fingers and hope for a refund or a replacement module that will actually work.

When you use the award-winning Crucial Memory Selector™, we guarantee that the memory you purchase is 100% compatible with your system or we'll give you your money back. We've done the work for you. You don't need to understand the nuances of memory technology. You only need to trust that when we say compatibility, we mean compatibility. The Memory Selector will only return those parts that we guarantee will work. Anything less — or less expensive — is a compatibility risk, and we'll tell you so.


--end--

[mylanta]

You know once again it goes to show you that Ram is one place you just cannot screw around with. Power supplies is another. For years it has astonished me that power users will spend $225 on a mobo, $700 on a cpu, and $19 on a psu and $75 on a gig of ram, and then they post and post and post on forums their new builds won't boot. Then there are the ones who spend $500 on a video card, $800 on a cpu and $48 on a mobo and the same $19 on psu and have the same problems. If the mobo, psu and ram are not right, that unit will torture you.
It will take years off your life!
Some clown on another forum PL and I are on, is actually jumping us for sending users to Crucial or Kingson or Corsair all the time for matching, and the poor fool doesn't get it that we are not sending the user there to buy the ram necessarily, or sell for those guys, but rather to find the model they need which they can then buy anywhere, but the configurators short cut so much of the process and insure the choice will be correct. And crucial is micron ram which is amongst the best anyway.

[dbarrow]

Nice advertising pitch but there are other considerations.
If you stick with the "configurator" and compatibility lists offered by all of the big name ram makers, you are usually good to go.
Note that the mobo makers also offer a list.

The problem is...
Many of these tests are done pre-release, before the mnfr releases the mobo for sale and with only preliminary tests.
Actual customer use often proves otherwise.
BIOS updates are predominantly fixes for ram compatibility after they find problems (if you find the BIOS release notes, you may see that kind of update stated in them).

I usually watch forums that deal with a specific mobo or ram and watch actual consumer comments.
You usually see, within a month or so of a mobo release,
brand A with X chips works perfectly or better than anticipated, brand B with the same X chips has errors, mobo flat out refuses to run with brand C with the same X chips.
Mobos can be just plain picky about ram sometimes.
While they may have 4 slots, some ram will only run in 2 stick combinations or limits speed and settings in 4 stick configuration. Some will prove out like: you can run 2 sticks with X chips per side in slot 1&3 but not 4 sticks. Or, you can run 2 sticks with X chips per side in slot 1&2 but not in slot 3 or 4. Correct combinations and slots can be important.

Voltages can be a factor.
Most ram can take a healthy over volt setting and in some cases ends up requiring a bump to make it rock steady.
Note Corsair and Crucial often list considerable head room in this area and often recommend running it at a higher voltage. Some memory errors are often cured by bumping the ram voltage a tad.

The key is extensive reading about a particular mobo in the first month or so after it comes out and watching for user comments.
(I note the Corsair forum where I have seen a complaint thread about a particular ram ends up with "don't use it with that mobo")

Then there is "vanishing ram".
So you get a stick or two of the perfect stuff.
Six months later, the maker of that ram has changed chips and no longer offers the same matching stick as what you have. Try and mate it with a similar but different stick and things go sour. You are often left with no choice but to replace the original stick with a matching set of something else.
Remember the famous Winbond chips that were the ultimate performer, until the factory burned down?
(fortunate enough to have gotten a pair of them and they kick butt!)

So... when building, choose the best ram (by comments) you can and spend the bucks to buy the maximum amount of matching sticks that you will ever put in the machine.
Don't plan on finding another stick of the same in six months (or as little as 3 in some cases). Get it now and be done with it because you won't find it again in the near future.

Unfortunately, as the mobo ages, finding all this info gets very difficult as the posts vanish. Once the mobo gets a few years old, it becomes a total crapshoot. (and note that prices on the older stuff have a sharp price curve during the "popular" phase for that mobo/chipset afterwhich they often rise considerably as demand diminishes).

Sometimes you get plain lucky buying the cheap "no name" sticks when the big names dump off their stock of leftover chips (note that most ram chips on the stick come from only one or two factories and despite the brand name on it, have the same chips). You may find a "no name" cheap stick with good chips at a bargain price that will do as well as the high price name brand but it's luck of the draw. There are a lot of them out there but strictly pot luck. The price is low because they don't back them with any exchange warantee like a Corsair or Crucial. You get what you get. It works, or not.

Not that PNY (or some of the other uncommon brands) off the shelf at Compusa are crap, sometimes they work just fine as long as you don't push them or expect low latency.
In a pinch, they can often be a bargain.

When building a performance machine, ram and latency can be as big (or bigger) performance factor than the CPU. Hit the "sweet spot" with a performance stick that just happens to be the right one for the overall combination and your machine will zoom zoom. Get the wrong combination and it can be a real dog.

Lastly, there is "memory leakage" where you have subtle memory errors. Not sufficient in number to crash your machine (until you run a game or run a really demanding task), but frequent enough to cause data loss in files.
Slow but eventual corruption of files until things start to crash unexpectedly as bit by bit, files slowly degrade on each read/write cycle.

Anytime you make a ram change or adjust timings or overclock, be sure to run Memtest and Prime95 for at least a day or two to look for memory errors. If your tests can't get past 24 hours without errors, you will eventually have some major problems which may not become evident until months of use. When you eventually start showing all kinds of file corruption, suspect the ram (symptom often attributed to a HD going bad).

[mylanta]

Doug,
As usual quite detailed and concise, but you sort of skirt around one thing which is the mobo mfgrs do at best a "half assed" job of listing compatible ram. They list half of them and in many cases there are mobo mfgrs that list nothing. The ram makers have more stake in the listings which is why they are so much more thorough.