2.87gb RAM usable out of 4gb? help please.

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RaptorZX3
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2.87gb RAM usable out of 4gb? help please.

Post by RaptorZX3 » Sun Jul 06, 2014 1:58 pm

Ok i recently added more RAM to a MicroATX board i have here, which only have 2 slots for RAM. But it only show 2.87gb usable on 4gb. I tried swapping the RAM and it's doing nothing, i used Memtest and it pass (twice).

Both RAM are the same brand (Kingston), same speed (667), and same model number (2G-UDIMM i believe). The board i use is an Asrock Conroe1333-667 Rev.1.0:
http://www.asrock.com/mb/intel/conroe1333-d667%20r1.0/

Some say it's 2.87gb due to the Intel 945 chipset it use, reserving memory for other things, is that true? (this board do support up to 4gb though, and i have the latest BIOS on it as well!)

CA_Steve
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Re: 2.87gb RAM usable out of 4gb? help please.

Post by CA_Steve » Sun Jul 06, 2014 2:12 pm

My guess is you are running a 32-bit OS: that limits total memory addressing (DRAM, VRAM, etc) to 4GB total. Time to move to 64-bit.

RaptorZX3
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Re: 2.87gb RAM usable out of 4gb? help please.

Post by RaptorZX3 » Sun Jul 06, 2014 2:14 pm

no it's Windows 7 Ultimate 64-bit

yakuman
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Re: 2.87gb RAM usable out of 4gb? help please.

Post by yakuman » Sun Jul 06, 2014 2:35 pm

If you're using an integrated graphics card like my Intel HD Graphics, it uses your RAM.

RaptorZX3
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Re: 2.87gb RAM usable out of 4gb? help please.

Post by RaptorZX3 » Sun Jul 06, 2014 2:49 pm

well it's true i didn't specified...i use a Geforce GTX295 card in it, it's not the latest fastest PC, but it can still be pretty good for games that doesn't need a super computer, and to play older games from the 2004-2008 era in general.

washu
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Re: 2.87gb RAM usable out of 4gb? help please.

Post by washu » Sun Jul 06, 2014 5:27 pm

The 945 chipset cannot remap memory above 4GB so any memory addresses taken up by your video card and other devices is simply lost. Doesn't matter if the OS is 64 bit or not.

RaptorZX3
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Re: 2.87gb RAM usable out of 4gb? help please.

Post by RaptorZX3 » Sun Jul 06, 2014 7:47 pm

the thing is the board have 2 slots, and 2gb in each, so how can i lose that much memory when i have a dedicated video card and all that with a 64-bit OS?

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Re: 2.87gb RAM usable out of 4gb? help please.

Post by CA_Steve » Sun Jul 06, 2014 8:05 pm

Doesn't matter whether it's a discrete video card, it's 1GB gets counted against the 4GB limit of the chipset.

washu
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Re: 2.87gb RAM usable out of 4gb? help please.

Post by washu » Sun Jul 06, 2014 8:06 pm

RaptorZX3 wrote:the thing is the board have 2 slots, and 2gb in each, so how can i lose that much memory when i have a dedicated video card and all that with a 64-bit OS?
Simple, the chipset physically cannot address more than 4GB. Your video card's memory has to fit into the address space, which displaces the RAM. In fact you are lucky that it looks like only one of the two memory banks on the 295 are getting mapped into the address space. If both banks were in your address space you would only have about 2 GB usable.

4GB minus 896 MB video RAM minus ~256 MB other PCIe address space = 2.87 GB usable.

In newer chipsets that "displaced" RAM gets remapped above 4GB so a 64 bit OS can use it. The 945 cannot do that.

RaptorZX3
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Re: 2.87gb RAM usable out of 4gb? help please.

Post by RaptorZX3 » Sun Jul 06, 2014 8:38 pm

so if i get a slightly newer MicroATX board without the 945 chipset, but still using DDR2, i should use it, right?

washu
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Re: 2.87gb RAM usable out of 4gb? help please.

Post by washu » Sun Jul 06, 2014 8:50 pm

RaptorZX3 wrote:so if i get a slightly newer MicroATX board without the 945 chipset, but still using DDR2, i should use it, right?
Make sure it actually supports memory remapping, but in general yes. I've seen a few 965 boards that did not enable memory remapping even though the chipset supports it. Others have the option default to off in the BIOS.

Your best bet is a board with the P45 chipset*. That supports up to 16 GB of RAM and also gives you PCIe 2.0.

* Unless you are running a P4 and not a Core 2 on your 945 board. Past the 945 chipset P4 support is hit or miss.

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Re: 2.87gb RAM usable out of 4gb? help please.

Post by RaptorZX3 » Sun Jul 06, 2014 8:51 pm

i do have a Core 2 Duo E8400 on it, LGA775.

Any mATX boards i should look for this CPU which will see up to 4gb available RAM?

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Re: 2.87gb RAM usable out of 4gb? help please.

Post by faugusztin » Mon Jul 07, 2014 2:08 am

As it was said, it's the chipset. i945 has a 32-bit memory controller, so while the rest of the system could run well with 64-bit stuff (software, drivers etc), it simply has no hardware to address more than 4GB of memory. And because you got hardware which also needs address space, the usable space drops to 2.87GB.

The primary question is if it is worth to invest in LGA775 at all. You will pretty much see boards only on eBay, and you are looking at $100+ price range for the usable boards.

If you don't mind losing old hardware, you could get a Pentium G3258 ($75), 4GB DDR3 ($35) and an ASRock Z97 Aniversary ($94.99). While it would be $210 in total, for $80-100 more than a Socket 775 board you could get a CPU which you could overclock to 4.5GHz and beat most of the current i3's and run rounds around your good old E8400. And of course you could sell your old CPU, seems like they go for $30 on eBay. That would bring the difference between the old and new system down to $50-$70. And of course the power consumption would drop too.

RaptorZX3
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Re: 2.87gb RAM usable out of 4gb? help please.

Post by RaptorZX3 » Mon Jul 07, 2014 2:32 am

thing is i can get older PC stuff for really cheap sometimes around my location...like the base of this computer (case, psu, board, cpu, hard disk, DVD drive, RAM...), i got it for free...but yeah since then i swapped parts in it.

So should i take out a 2gb stick from this computer to replace it for a 1gb instead, to have in total 3gb and losing dual-channel?

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Re: 2.87gb RAM usable out of 4gb? help please.

Post by faugusztin » Mon Jul 07, 2014 3:34 am

You won't get 3GB. 2.87GB is the maximum you can get, because total address space of your PC is 4GB, and your hardware devices need 1.13GB of that address space.

As it was said, your best bet to reuse that CPU, while having 4GB or more RAM is to get a board with P35/P45/G41/G45/Q45 chipset. That means for example P5K and P5Q series from ASUS, if it has to be mATX then i would try to get P5Q-EM.

RaptorZX3
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Re: 2.87gb RAM usable out of 4gb? help please.

Post by RaptorZX3 » Mon Jul 07, 2014 3:47 am

I checked and what bother me with the Asus P5K-VM nd many other potentially suitables is the PCI-Express 16x use the 2nd slot, so that mean 2nd and 3rd slot will be taen and way too little space left for intake for a slot blower to help with cooling. It would be best if the PCIe 16x would use the 1st slot...yet, so many tend to use the 2nd one instead for mATX boards of this generation.

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Re: 2.87gb RAM usable out of 4gb? help please.

Post by quest_for_silence » Mon Jul 07, 2014 4:12 am

RaptorZX3 wrote:to have in total 3gb and losing dual-channel?

To gain about 130Mb of more RAM? Do you think you will gain any performance advantage?

washu
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Re: 2.87gb RAM usable out of 4gb? help please.

Post by washu » Mon Jul 07, 2014 5:30 am

quest_for_silence wrote: To gain about 130Mb of more RAM? Do you think you will gain any performance advantage?
There would be no memory gain, not even 130 MB. The address space would still be used.

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Re: 2.87gb RAM usable out of 4gb? help please.

Post by washu » Mon Jul 07, 2014 5:34 am

RaptorZX3 wrote:i do have a Core 2 Duo E8400 on it, LGA775.
While your MB "supports" this CPU, the E8400's 1333MHz FSB is *VERY* out of spec for the 945. Not a good idea.

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Re: 2.87gb RAM usable out of 4gb? help please.

Post by quest_for_silence » Mon Jul 07, 2014 6:32 am

washu wrote:There would be no memory gain, not even 130 MB. The address space would still be used.

Yes, I stand corrected.

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Re: 2.87gb RAM usable out of 4gb? help please.

Post by edh » Mon Jul 07, 2014 8:42 am

I would agree with those who question the value of upgrading the motherboard on a system of this age. Unless you really can find it for free, it's not worth it.

RaptorZX3
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Re: 2.87gb RAM usable out of 4gb? help please.

Post by RaptorZX3 » Mon Jul 07, 2014 5:13 pm

well it's more for the speed and cache size i got the E8400 on it, i tried Just Cause 2 on it, with fairly high details, and it seem to run fine on it.

I paid like 20$ for the E8400, i already had an Antec Truepower 550W for it (used converters for the GTX295 (single board, not the old model) since it doesn't have the PCIe plugs on it), so...if i can find a board for cheap, supporting this CPU, PCIe on the 1st slot, supporting memory remap, 2 or 4 RAM slots, of even a Mini-ITX (guess it can still work in this case), it would be just fine then.

But yeah, i won't pay too much for that kind of board, if someone is getting rid of it, then i'll be taking it to use it.

I really hate it when peoples send their stuff for recycling when that stuff still work! instead they should give it to someone who will use that, and if they're too worried about their data, then i don't care i can take the HDD out, or i'll make sure to tell them i'll do a full data wipe on it before using it.

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Re: 2.87gb RAM usable out of 4gb? help please.

Post by xan_user » Mon Jul 07, 2014 7:57 pm

I always donate my unused electronics to the local educational non profit. they train people with them, give sytems away to the needy and sell the rest to keep the doors open and the lights on.

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Re: 2.87gb RAM usable out of 4gb? help please.

Post by washu » Tue Jul 08, 2014 7:09 am

RaptorZX3 wrote:well it's more for the speed and cache size i got the E8400 on it, i tried Just Cause 2 on it, with fairly high details, and it seem to run fine on it.
There is nothing wrong with the E8400, it's a good CPU. You are just seriously overclocking the FSB of the chipset to run it.
Antec Truepower 550W for it (used converters for the GTX295 (single board, not the old model) since it doesn't have the PCIe plugs on it),
If you really have such an old Truepower 550 that it lacks PCIe connectors then you are in a very bad situation. Your GTX295 alone takes more 12V current than the old TP550 is rated for. When you are gaming you are seriously over stressing your PS. Combine that with its age and that it likely has bad caps and you have a ticking time bomb on your hands. When (not if) your PS blows there is a good chance it will take other hardware with it. On top of all that, using molex->PCIe adapters on such a power hungry card is a fire hazard.

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Re: 2.87gb RAM usable out of 4gb? help please.

Post by RaptorZX3 » Tue Jul 08, 2014 9:45 am

well the Antec TP 550W have 2x PCIe 6pins on it, i'm using a 2x Molex to 1x PCIe 6pins, and a 2x PCIe 6pins to 1x PCIe 8pins. I don't have any other powerful-enough PSU for it, and so far it seem to be alright. The E8400 itself isn't overclocked on that board, and i had to tweak some stuff in the BIOS so it wouldn't overclock, in fact, it's very slightly underclocked (running around 2.95Ghz or something instead of 3Ghz), because with overclocking it seem to reboot the computer constantly, even with only on-board video it does that, and with any power supply (it had a crappy 400W PSU initially, with an E6550 previously).

I did many OCCT stability tests on it, including "power supply" benchmarks, for about 1 hour each one, and everything seem to be working alright on this computer.

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Re: 2.87gb RAM usable out of 4gb? help please.

Post by washu » Tue Jul 08, 2014 10:07 am

Ok, that sounds like a Truepower 550W v2.0, not the original. That is fine, but close.

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