Yes there is a reason for the 3 blue and 1 black ram slots. This board supports triple channel memory (memory in groups of 3) to get the best performance you want to make sure that the memory is put in that way. Now since this board doesnt have 6 slots for memory what happens with the 4th slot (black) is that it assigns it to the first channel.
Yes you can put 2 sticks of memory in but you would be better off if you put 3 sticks of memory in it.
What G>Skill Memory should I buy? I just live chatted a intel agent and this is what he told me.
Michael: Hello. Thank you for using the Intel Customer Chat Support service. We are glad to be of service. How may I help you?
: Hi I have a question
: I have an Intel DX58SO motherboard
: and I wanted to ask
: there are 3 blue ram slots and 1 black ram slots
: whats the difference?
Michael: you have to populate the blue memory slots first
Michael: but either blue or black memory slots are the same
: one more thing
: I'm going to buy this ram
: G.Skill RipJaws X (dual) 2x4gb ddr3 1600 CL9 (F3 12800CL9D 8GBXL)
: its gonna be a 4x4 so 16gb all in all
: will this have anyproblems?
Michael: what is your processor model?
: Corei-7 920
: I went over to the tested memory section
: I don't see any G.SKill brand
Michael: I recommend to get memory that is DDR3-800/1066 at 1.5v. For more memory specifications please go here:
: ddr3 800/1066?
: right now i'm running on Kingston 4gb DDr3 1333
: 2 of them
: so I can still get those 4 g.skill rams to run on my system?
Michael: No because is 1600 MHZ
: what about this
: G.Skill RipJaws X (Dual) 2x4gb ddr3 1333 CL9 (F3 10666CL9D 8GBXL)
: a 1333 ddr3 one
: same frequency like the kingston i have right now?
Michael: I understand but we do not recommend that memory since later on it could damage the memory controller
Here is the thing. The Intel® Core™ i7-920 supports memory at 800/1066 without overclocking. Now if you buy memory that is faster then that most likely it simply downclock it to run at that speed unless you set it on the bios. Since we don't support you overclocking that is a risk you take if you try to run faster memory.
The most important part is to make sure whatever memory you select is running at 1.5v. I have heard more people who have damaged their processor by using memory that is at higher then supported voltage.
I am saying that you can put faster memory (i.e. DDR 3 1333, 1600, 1833 etc.) on the board if the board supports and do so without much of a problem; it would still be overclocking. Now if you put memory on the board that is 1.65v + there is a chance that you are going to damage the processor's memory controller.
Now both of these actions are likely to void for your warranty but the using high voltage memory stands a much higher chance of damaging your processor then running faster memory. So for the processor you are looking at DDR 3 memory 800/1066 at 1.5v ±5% (1.425v to 1.575v) being supported on the board.
Now for supported memory on the board you are look at...
Four 240-pin Double Data Rate 3 (DDR3) SDRAM Dual Inline Memory Module (DIMM) connectors with gold-plated contacts arranged in two channels
1600+/1333/1066 MHz DDR3 SDRAM Memory Modules
Three independent memory channels with interleaved mode support
Unbuffered, non-registered single- or double-sided DIMMs with a voltage rating of 1.65 V or less
16 GB maximum total system memory (with 2 Gb memory technology).
Minimum total system memory: 1 GB using 512 MB x16 module
Serial Presence Detect
XMP version 1.2 performance profile support is required for memory speeds above 1333 MHz or use of manual adjustments
So there is a difference between the supported memory for the board and the CPU but I would focus on what is supported on the processor. In the end you could put some DDR 3 1600 1.5v and on the board and never have a problem but if you did need to call our techical support that configuration wouldnt be supported by them if you were having issues.
Don't get me started about 'that' MOBO, and unless you need more than 3x4GB (12GB) the smartest option is to get a Tri Channel kit and running DDR3-1600 on the i7-920 is a piece of cake and doesn't require much more than going in the BIOS and Enabling XMP and Profile 1.