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PC sees 3 Gig but says it's better with 4


Ponch
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I got that Packard Bell laptop from a friend, which was going to bin it because it was making an awfull noise (I solved that in 3minutes). Nice screen, 1440 x 900, annoying keyboard (or is it because it needs the screws back on?).

Anyway... The thing, that is not listed on Packard Bell's site (Easynote SW51-204) has an nvidia chipset. It had 2x 512 Meg installed. I test a 2Gig stick and it was seeing it all right. So I grabbed a bargain on eBay to put 2x2Gig DDR2-6400 in it.

Unfortunately, the Bios as well as Windows7 only report 3Gig (Windows really says 4Gig but 2.87 usable because the graphic card uses 128Meg). So I replaced one stick by 1Gig DDR2-6400. Well... it then says the RAM is slower! I tried to swap the sticks but it's the same result.

HW-Info tells the same story for all scenarios (2+2, 1+2 or 2+1);

 [General information]  Total Memory Size:                      4 GBytes  Total Memory Size [MB]:                 4096 [Current Performance Settings]  Current Memory Clock:                   320.7 MHz  Current Timing (tCAS-tRCD-tRP-tRAS):    5.0-5-5-15  Memory Runs At:                         Dual-Channel  Command Rate:                           2T  Write to Read Delay (tWR_RD) Same Rank (tWTR): 3T  Write to Precharge Delay (tWTP):        16T  Write Recovery Time (tWR):              5T  Row Cycle Time (tRC):                   21T  Four Activate Window (tFAW):            13T
[General information]  Total Memory Size:                      3 GBytes  Total Memory Size [MB]:                 3072[Current Performance Settings]  Current Memory Clock:                   320.7 MHz  Current Timing (tCAS-tRCD-tRP-tRAS):    5.0-5-5-15  Memory Runs At:                         Dual-Channel  Command Rate:                           2T  Write to Read Delay (tWR_RD) Same Rank (tWTR):    3T  Write to Precharge Delay (tWTP):        16T  Write Recovery Time (tWR):              5T  Row Cycle Time (tRC):                   21T  Four Activate Window (tFAW):            13T

Still, the "Benchmark" says 1800MB/s for 4Gig and 1596MB/s for 3Gig! Windows Performance index also gives less for RAM speed with 3Gig.

Can someone explain that to me? I'm quite frustrated to loose a whole Gigabyte for 13% more speed. Is this a 100% hardware problem?( there is no Bios info/update that I can find).

Edited by Ponch
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Two things to note. It appears that chipset will allocate 512MB to the video controller.

Memory Allocation Technology TurboCache supporting 512MB

http://www.backoffice.be/prod_uk/Packard_Bell/pb57c00390_packard_bell_easy_note_sw51-204_turion_64_x2_tl.asp

Second, in the 1+2 or 2+1 configuration, you are running in single channel. Using the matched set you are in dual channel. Some benchmark tests will show memory running in dual channel to be "faster" as can be seen here:

http://www.gamersnexus.net/guides/1349-ram-how-dual-channel-works-vs-single-channel/Page-3

See the MaxxMem one for example.

Can you post screenshots from CPU-Z showing the SPD for each stick? Also post the model numbers physically printed on each piece for comparison.

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And I guess you have not the guts :w00t::ph34r: to patch the Windows 7 (32 bit) to allow it seeing the whole 4Gb, right? :whistle:

Is this a real question? Well if he Bios only "half sees" them (in fact I'll edit my 1st post, Windows does say "4GB, 2.87 usable"), there's very little chance that it could solve the problem. I'll send you my Bios as an ascii file and see if you got the guts to patch it. :rolleyes:

For the video card, there is no menu in Bios to change those 128MB.

Here are the SPD's:

post-80608-0-30149700-1420143628_thumb.j  post-80608-0-65849700-1420143640_thumb.j

 

both 2Gig are identical and are; Hynix 2GB 2Rx8   PC2-6400S - 666- 12         HYMP125S64- S6 AB

the 1Gig reads                     Samsung 1GB 2Rx16 PC2-6400S - 666- 12 -A3   M470T2864QZ3-CF7   0931

 

While I do understand that dual channel is better than single, I don't see why HWinfo32 reports the memory as running Dual Channel but then bechmarks as single channel. Maybe he report only checks the beginning of the memory (maybe it goes dual channel up to the 1st 2Gigs then single channel for the remaining Gig of the 2Gig stick???). Cheers.

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And I guess you have not the guts :w00t::ph34r: to patch the Windows 7 (32 bit) to allow it seeing the whole 4Gb, right? :whistle:

 

Is this a real question? Well if he Bios only "half sees" them (in fact I'll edit my 1st post, Windows does say "4GB, 2.87 usable"), there's very little chance that it could solve the problem. I'll send you my Bios as an ascii file and see if you got the guts to patch it. :rolleyes:

For the video card, there is no menu in Bios to change those 128MB.

 

While he is half-joking, jaclaz is right, it can be done and does solve the problem (<link>), but it's frowned upon by MS.

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The SPD looks good. The only reason I asked for it was because you can run into RAM sticks that are re-labelled. ;)

While I do understand that dual channel is better than single, I don't see why HWinfo32 reports the memory as running Dual Channel but then bechmarks as single channel. Maybe he report only checks the beginning of the memory (maybe it goes dual channel up to the 1st 2Gigs then single channel for the remaining Gig of the 2Gig stick???). Cheers.

Well I don't think your benchmark is "testing" as single channel. It either is or it isn't. AFAIK, these tools merely read the state from the BIOS. It could either be a reporting error or a reading error. I looked up Hwinfo32 and see that it has detection for single/dual/quad per chipset. On the Memory tab of CPU-Z, there is a Channel # field. When you have the mismatching pair in, what does it say? If it says Single (as I would expect) then see if there is a newer version of hwinfo32... or if that doesn't work then perhaps file a bug report?

However, if CPU-Z also says dual channel with the mismatched set, then the problem might stem from the system itself.

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Well I don't think your benchmark is "testing" as single channel.

I meant "the benchmark results looked like it was single channel". For the rest, you are right, CPU-Z says it's single channel, while the latest HWinfo32 reports dual channel. So I got my answer. Thanks.

@Dencorso, I bet Windows 7-64bits would tell me exactly the same (if (?) you read the 1st post).

Then some smart people would tell me "there is no gain on a sub 4GB system anyway". I know the songs here.

There's a reason I posted this in the hardware forum. :P

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Then some smart people would tell me "there is no gain on a sub 4GB system anyway". I know the songs here.

There's a reason I posted this in the hardware forum. :P

Well I could use the example that 512MB RDRAM was better than 2GB DDR... :P

Anyways, when it comes to computing it really comes down to what works best for you. I'm certain there are still those out there that wish to participate in RAM stick measuring contests, but whatever works for you is just fine. :D

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Of course i was half-joking :), but you seemingly have not checked if (as I believe) the "2.87" is caused by just the OS, by a "specific" combination of BIOS+OS or by the BIOS alone.

 

What do you see (without any fancy benchmark tool) in Windows 7 Resource Monitor, like, you know:

 

 

This:

4.jpg

 

Or this ;):

3.1.jpg

 

 

jaclaz

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It's worse than that. With 2+2 it says

-Hardware Reserved:  1153 (which I translate in ~1024 "lost"+128 VGA)

-Total:  2943 (which translates in ~3x1024 "seen" -128VGA)

-Installed:  4096MB (which decency forbids me to translate)

It's just psychologically annoying. Such bios limitations would not "hurt" us if there were 3 memory slots, it just feels wrong on 2.

+Actually the bios only allows me to set less than 128Meg of shared memory (128, 64 or 32, ...or "Auto" that comes to 128).

As the laptop was sold with XP Mediacenter and 1024Meg, it made sense to have only 1/8 of the RAM shared. Case closed I guess.

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Worse or better, it still seems to me like the issue is not in the BIOS but rather in the limit within the Windows 7 kernel.

 

I.e., if you prefer, it is likely that if you try patching the OS, you will be able to have:

 

-Hardware Reserved: 128 (which decency forbids me to translate)
-Total: 3967 (which translates in ~4x1024 "seen" -128VGA)
-Installed: 4096MB (which decency forbids me to translate)

 

jaclaz

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Jaclaz, the issue is the Bios. It only sees 3Gig and will only allow Windows to use 3Gigs. While Wndows is aware that there are 2 sticks of both 2Gigs, it will only be given 3, not 3.5, not 3.25, but 3Gigs. This is not a 32bit vs 64bits OS issue. This is the hardware forum. ;)  Case closed.

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Hey, you posted here:

 

 

(in fact I'll edit my 1st post, Windows does say "4GB, 2.87 usable"), there's very little chance that it could solve the problem.

 

I took that to be (with different values) the same that you can see in the screenshot I posted in Windows Resource monitor.

 

If you are sure that this is not your case, my bad :( though I am of course happy :) that the case is closed.

 

As a side note, it is really sad how I spent all these years in believing that the HAL (Hardware Abstraction Layer) was actually a hardware abstraction layer and that it was hardware related. 

 

jaclaz

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Ponch, no offense meant and I could be wrong, but I think that jaclaz is correct.  Regardless of what the BOIS says, I think that the Windows kernel is "artificially" limiting Windows to 3GB and by patching it you would be able to use the full 4GB.

 

Cheers and Regards

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Ponch, with all due respect, both NT-family and unix-family OSes do fully supersede BIOS during the boot process. Hence, unless the machine's chipset does not contain a memory hoist, no matter what the BIOS thinks, those OSes can access all (or almost all) installed memory.

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