Motherboard DDR400 problem - Page 1
Forum section: electronics / general

author: Bibiricat
author_rank: Contributor
timestamp: May 11, 2013, 07:23:25 pm
content: Hello.I recently bought 1 more Gb of DDR400 , 2x512, dual channel( i already had 2x512 DDR400), and when i installed it, it the bios detects all 4 boards just fine, but says only have 1.5 Gb of RAM.I have this motherboardhttp://www.asrock.com/mb/ULi/939A8X-M/witch can support up to 4Gb of RAM.Any idea on what is the cause of this, and how can i fix it ?PS: I posted here because i didn't know where else to post it

author: Bibiricat
author_rank: Contributor
timestamp: May 11, 2013, 08:17:47 pm
content: I did some test, and with any of the 4 RAM combinations, in dual channel, the BIOS sees them correctly.When i add the 3rd RAM , it recognizes it, but still shows 1Gb total memory ( with the RAM in any of the 2 remaining slots) and only when i add the 4th one , it shows 1.5Gb total.

author: justanothercanuck
author_rank: Frequent Contributor
timestamp: May 11, 2013, 08:38:21 pm
content: are you putting the sticks in the right slots? i believe you have to put them in with matched pairs... ie: one pair goes in the blue slots, the other goes in the black slots...another thing i can think of is that the new memory isn't the same specs as the old memory (maybe not FSB speed, but other things like CAS/RAS stuff)... if you're using automatic SPD settings you might want to set them to the higher of the two settings.have you tested the new memory in another computer, or by itself?

author: mariush
author_rank: Super Contributor
timestamp: May 11, 2013, 09:07:03 pm
content: In addition to the stuff below, the mainboard may support 4 memory modules only if they're SS (single sided DDR1) - you may have one pair or both pairs in doube sided configuration (note: it's not always about the physical layout of the chips on the memory module). Unfortunately the Asrock website doesn't say anything about qualified memory modules so I can't check this.Otherwise :Manual :ftp://europe.asrock.com/manual/939A8X-M.pdfPage 122.3 Installation of Memory Modules (DIMM)939A8X-M motherboard provides four 184-pin DDR (Double Data Rate) DIMM slots, and supports Dual Channel Memory Technology.For dual channel configuration, you always need to installidentical(the same brand, speed, size and chip-type)DDR DIMM pair in the slots of the same color. In other words, you have to installidentical DDR DIMM pair in Dual Channel A (DDR1 and DDR2; Blue slots; see p.8 No. 6) oridentical DDR DIMM pair in Dual Channel B (DDR3 and DDR4; Black slots; see p.8 No. 7), so that Dual Channel Memory Technology can be activated.This motherboard also allows you to install four DDR DIMMs for dual channel configuration, andplease install identical DDR DIMMs in all four slots. You may refer to the Dual ChannelMemory Configuration Table below.Dual Channel Memory ConfigurationsDDR1 DDR2 DDR3 DDR4(Blue Slot) (Blue Slot) (Black Slot) (Black Slot)(1) Populated Populated - -(2) - - Populated Populated(3)* Populated Populated Populated Populated* For the configuration (3), please install identical DDR DIMMs in all four slots.* It is recommended to install DDR3 and DDR4 (black slots) first. Then to install in DDR1 and DDR2. (That is, to populate DDR DIMM from the far side of CPU towards to the near side of CPU.)

author: Bibiricat
author_rank: Contributor
timestamp: May 11, 2013, 10:07:08 pm
content: I tested them in dual channel configuration, on the same PC.I have 2 identical double sided RAM :KINGMAX 512MB PC3200 DDR400 MHzAnother single sided KINGMAXAnd the last one is double sided , but it's made by someone else.All 4 have the same specifications, and the PC worked for 4 years with the last 2 mounted in dual channel config.The 2 identical RAM boards are in dual channel config, and the last 2 are also in dual channel.

author: Bibiricat
author_rank: Contributor
timestamp: May 11, 2013, 10:13:32 pm
content: Thanks for the info.Tomorrow i will flip them around, to see what happens.I will install the 2 identical RAM modules in slots 3 and 4, and the different ones in slots 1 and 2, and see what happens. If it doesn't work, i will probably end up buying another Kingmax module.

author: amyk
author_rank: Super Contributor
timestamp: May 12, 2013, 10:30:24 am
content: Quote from: Bibiricat on May 11, 2013, 10:07:08 pmMixed RAM may or may not work.In my experience lesser-known chipsets tend to be less flexible with mixed configs.

author: lewis
author_rank: Frequent Contributor
timestamp: May 12, 2013, 10:38:53 am
content: Has the 'missing' 512MB been reserved for onboard graphics? Have a look in the bios for 'graphics aperture size' or something like that.

author: Bibiricat
author_rank: Contributor
timestamp: May 12, 2013, 11:03:39 am
content: There is no onboard graphics card, and the missing ram only spears after i install the firs 1Gb of RAM