Using both PCI x16 and x8 without slowing x16 slot down?

holygamer · 1 Jan 2016 at 03:36

My existing motherboard has this in the manual:

The PCIEX8 slot shares bandwidth with the PCIEX16 slot. When PCIEX8 is populated with a card, the PCIEX16 slot will operate at up to x8 mode.

I'm going to be using an Intel i7 5960X and I'll be overclocking it to at least 4Ghz. Will also be using 64GB DDR4 RAM. Slots should be PCI Express 3. I'll be using a SATA III card in either a x8 or x16 slot. Will also be using a powerful graphics card in an x16 slot. I would like the graphics card slow to NOT be slowed down due to the other slot being occupied by the SATA card.

Is there a motherboard which offers that (Slots should be PCI Express 3)? Should I get a motherboard with 2 x16 slots? If I put my SATA card in the x8 slot or x16 and 1 graphics card in an x16 slotsthen does that mean that the SATA card is only slowing down one of the x16 slots?

ninjah · 1 Jan 2016 at 04:11

What is your pic spec?

holygamer · 1 Jan 2016 at 04:12

What do you mean?

queamin · 1 Jan 2016 at 05:03

What version is it 2 or 3?

holygamer · 1 Jan 2016 at 05:28

PCI Express 3

queamin · 1 Jan 2016 at 07:13

x8 PCI Express 3 is fine you will not lose that much performance at all, but at 4k I am not sure if it will matter, someone could tell you if you going to game at 4k what you could lose.

freddie64 · 1 Jan 2016 at 08:49

If you want 2 x PCIEX16 slots that does not drop to PCIEX8, i think you need SKT 2011-V3

Like this for example.
My basket at Overclockers UK:

1 x MSI X99A SLI Plus Intel X99 (Socket 2011) DDR4 ATX Motherboard= £179.99

Total: £190.49
(includes shipping: £10.50)

Not a cheap option as you will need a CPU and RAM as well (unless you use DDR4 now).

My GPU is on PCIEX8 and i have no probs gaming. (not 4k)

pandem0nium · 1 Jan 2016 at 14:51

No only that, but you'd need a 5930k or better.

There won't be any performance issues running 2 cards in x8 mode.

holygamer · 1 Jan 2016 at 17:24

Just to be clear guys I'm going to be using an Intel i7 5960X and I'll be overclocking it to at least 4Ghz. Will also be using 64GB DDR4 RAM. Slots should be PCI Express 3. I'll be using a SATA III card in either a x8 or x16 slot. Will also be using a powerful graphics card in an x16 slot. I would like the graphics card slow to NOT be slowed down due to the other slot being occupied by the SATA card.

Kaapstad · 1 Jan 2016 at 17:32

holygamer said:
Just to be clear guys I'm going to be using an Intel i7 5960X and I'll be overclocking it to at least 4Ghz. Will also be using 64GB DDR4 RAM. Slots should be PCI Express 3. I'll be using a SATA III card in either a x8 or x16 slot. Will also be using a powerful graphics card in an x16 slot. I would like the graphics card slow to NOT be slowed down due to the other slot being occupied by the SATA card.

5960X and 4 Titan Xs

No slow down on any of them.

The bloke who owns them is a bit of an idiot though. :eek:

Trying · 1 Jan 2016 at 17:37

What SATA III card are you proposing to use, and what are you proposing to run off it.
Just wondering if you actually need to instal it in a PCIE 3.0 x 8 slot..or can you achieve your needs fitting it to a PCIE 3.0 x 4 slot?
I take it, it is all about bandwidth for your Sata needs.

holygamer · 1 Jan 2016 at 17:53

Kaapstad said:
5960X and 4 Titan Xs

No slow down on any of them.

The bloke who owns them is a bit of an idiot though.

OK but what motherboard is he using?

Trying said:
What SATA III card are you proposing to use, and what are you proposing to run off it.
Just wondering if you actually need to instal it in a PCIE 3.0 x 8 slot..or can you achieve your needs fitting it to a PCIE 3.0 x 4 slot?
I take it, it is all about bandwidth for your Sata needs.

8 Port Supermicro SAS/SATA Card (AOC-SAS2LP-MV8). It needs an x8 or x16 slot. Yes I need the bandwidth. I may decide to use something else instead of the Supermicro in future. I just need some assurance that whatever I use in the slot won't slow down a graphics card in a x16 slot.

Trying · 1 Jan 2016 at 20:09

holygamer said:
8 Port Supermicro SAS/SATA Card (AOC-SAS2LP-MV8). It needs an x8 or x16 slot. Yes I need the bandwidth. I may decide to use something else instead of the Supermicro in future. I just need some assurance that whatever I use in the slot won't slow down a graphics card in a x16 slot.

I note the required specs for that card are PCI-E x8 Gen 2.
Remember the current slots on your motherboard you are talking about are gen 3, aren't they?

What I am getting at, is the drain on the PCIE resources using slot 2 could well be less than you are thinking they may be.
I am no expert, but it may open up some new aspects to be thought through.

holygamer · 1 Jan 2016 at 21:53

I just want to play it safe and make sure I get a motherboard that will allow one of the x8 or x16 slots to NOT slow down the other x16 slot. Does anyone have any motherboard suggestions please?

Need a Turbo M.2 slot. I currently have a Gigabyte motherboard but I don't like it as the included fan control software doesn't seem to have any effect on the fans at all. I used to have an Asus motherboard and the fan software on that was perfect. My fans are 3 pin.

Trying · 1 Jan 2016 at 22:26

It may be worth your while checking this thread out.....
http://forums.overclockers.co.uk/showthread.php?t=18705906

in respect of the soon to be released Gigabyte GA-X99P-SLI (rev. 1.0)

holygamer · 1 Jan 2016 at 22:41

I don't want to use a Gigabyte motherboard as the fan software for it doesn't work.

Kaapstad · 1 Jan 2016 at 23:28

holygamer said:
OK but what motherboard is he using?

8 Port Supermicro SAS/SATA Card (AOC-SAS2LP-MV8). It needs an x8 or x16 slot. Yes I need the bandwidth. I may decide to use something else instead of the Supermicro in future. I just need some assurance that whatever I use in the slot won't slow down a graphics card in a x16 slot.

The motherboard is a Rampage V Extreme.

Having said that if you are using an 5960X most X99 motherboards will allow you to run either 2 x PCI-E 3.0 x16/x16 or 2 x PCI-E 3.0 x16/x8. With either setup you should get no loss of performance.

With PCI-E lanes, this is determined by what the CPU supports and IIRC the 5960X has 40 available.

All Haswell-E CPUs and X99 motherboards are PCI-E 3.0 capable.

Check out the specs of whatever motherboard you are interested to make sure they have 2 slots with x16/x16 or x16/x8 available and they are spaced a reasonable distance apart.

OracIe · 1 Jan 2016 at 23:38

Kaapstad said:
With PCI-E lanes, this is determined by what the CPU supports and IIRC the 5960X has 40 available.

Correct, as does the 5930K. The 5960X has 8 cores versus 6 of the 5930K.

holygamer · 2 Jan 2016 at 13:15

Thanks guys. I didn't realize the CPU determines how many lanes are supported. I never even new about "lanes" until now. Until now I was just looking for motherboards with 2 x16 slots!

Are there any motherboards with 2 M.2 slots?

FredFlint · 2 Jan 2016 at 15:25

Some Asrock boards have two m.2 slots.