16 Gb RAM in which slots?

[Strommer]

Christmas came early for me yesterday morning! Two courier packages delivered at 8 AM: Two pair of specs from Zenni Optical which I was expecting, and the nice surprise of new RAM that I ordered on eBay that came from the UK. I removed the two sticks of 4 Gb RAM and replaced it with the two new sticks of 8 Gb. Now my desktop has 16 GB of RAM and it is very sweet - I should have done it long ago but when I looked back then I could not find the correct RAM. So anyway my question is about what slots I should be using.

The RAM is in slots 1 and 3, which is what has always been the case. I now have found out that for Dual Channel I should be using slots 2 and 4 - is this correct? I assume slot #1 is at the far left and #4 at the far right.

Before you jump in and answer, have a look at what I have: I built my desktop ten years ago and it has been super, never any problems not even with all the Window version upgrades (Win10 is great for me). I have added a solid state HD for the OS since boot up time was slow using a mechanical HD. I also have two mechanical HD's for storage and back-up and will soon replace one of them to ensure all data remains OK.

The mobo is an ASUS M4A88TD-M. Although I ordered the USB-3 version from PB Tech, they sent me the USB-2 mobo and I did not realise the mistake until after everything was assembled [grizzle grrrr; I tried adding a USB-3 card in a spare mobo slot but it did not fit]. The CPU is AMD Phenom quad core. I added a small video card so that I could run dual monitors - I am not a gamer so no big graphic requirements. I use my desktop for the usual word processing, photo editing, occasional video editing, web browsing and it has all been good with no need for a new PC - except sometimes the 8 GB RAM was at its limit especially with multiple browser tabs.

Should I bother to re-insert the new RAM into slots 2 and 4 (instead of the current 1 and 3 slots)?

Should I even put the two old 4 Gb sticks of RAM into the spare slots so that the total would be 24 Gb. The old 4 Gb sticks are Corsair (Vengeance) and the new 8 Gb sticks are Crucial.

Thanks.

[dugimodo]

When the system is booting there should be a message telling you if the memory is in dual channel mode, if it is then don't worry about it. If it says single channel it is worth swapping them for the slight performance boost.
You should be fine how you have it, some motherboards are finicky about what slots you use and others less so.

Generally motherboards have 2 channels and group them like Slot 1 & 2 = channel 1, Slot 3 & 4 = channel 2 and for dual channel mode you need 1 stick in each channel, which you have.
Looking at your manual it actually doesn't specify what slots to use, all it says is if you have different amounts of memory in the two channels you'll get dual channel mode up to the amount of RAM that matches in each and that the excess will run in single channel mode. Seems like a very flexible motherboard.

It does say to not mix RAM with different CAS latency, so if you can figure that out for your new & old RAM see if it matches. Or just bung it all in and see what happens, if the system is unstable take the old RAM back out again.
Normally I wouldn't bother as 16Gb is enough for most people, but you have it so why not try it.

[piroska]

The RAM is in slots 1 and 3, which is what has always been the case. I now have found out that for Dual Channel I should be using slots 2 and 4 - is this correct?
The mobo is an ASUS M4A88TD-M.

.

On ASUS website, under that model is the manual.
It will tell you whether or not it matters,.

[Strommer]

Thanks dugimodo. I did look at the mobo manual but as you found, it does not specify what slots to use. The next time I take the covers off the case for blowing out the dust, or adding a new HD, I may try different slots or even adding the other 2 sticks of 4 Gb but for now it is running very sweet so I will leave it be.

With regards to adding USB-3, have a look at the available PCI slot here Do you have any idea if it is possible to add a USB-3 card here? When I tried this over a year ago, the USB-3 card did not fit (from memory, the number of pins/sockets were correct but inverted or something). Thanks. [edit: the long blue slot beneath the graphic card, not the short blue slot above]

[Strommer]

On ASUS website, under that model is the manual.
It will tell you whether or not it matters,.

The manual does not specify which slots for dual channel, but the specs does state 'dual channel architecture' so I think dual channel happens whatever slots are used. Here is the page from the manual:

[piroska]

Really, it's all in the manual, see:

[KarameaDave]

The small blue slot is PCI-E x1
That's where a USB3 card goes.

[Strommer]

Really, it's all in the manual, see:

Ah!! Thanks! Don't know how I missed that page. This morning I went into our storage room and emptied a cardboard box with computer items - at the bottom was the original mobo box, with printed manual. On page 1-12 there is a note (which I highlighted way back when I installed the mobo) that recommends using the blue slots (1 and 3) so as to get better overclocking. I never used overclocking and probably never will on any PC. Anyhow, now that I see page 1-11 that has the channels explained, it is still not clear to me what slots I should have put the two new sticks of 8 Gb RAM, but it is running so smoothly now I will leave it be.

[Strommer]

The small blue slot is PCI-E x1
That's where a USB3 card goes.

OK, thanks. I cannot recall why the USB card that I bought about a year ago would not fit. I will see if I can find it in the storage room (aka junk room). It would be great if I could get USB-3 on my desktop!

[Strommer]

It does say to not mix RAM with different CAS latency, so if you can figure that out for your new & old RAM see if it matches. Or just bung it all in and see what happens, if the system is unstable take the old RAM back out again.

I found the specs on the original two sticks of 4 Gb RAM, Corsair Vengeance. The latency is given, and of course the speeds. However I see that the new Crucial RAM, two sticks of 8 Gb has a different BUS and frequency speeds (the latency is not listed). So I am guessing that mixing the old and new sticks of RAM will not work - I may try it sometime to see what happens but at the moment 16 Gb of RAM is very sweet indeed.