processor

[turtles123]

on my next workstation i want to be able to use at least 2 graphic cards. right now i have the 770 gtx and the 960gtx, and i will brobably buy another one soon.

for the processor i was thinking about the i5 6600, does this processor have enought pci lanes (the 6600 has 16 pci lanes ) to use the graphic card at their full potential?
or i need a 40 pci lane processor to use 2 or 3 graphic cards?

thanks!

[karanis]

Hi,

the cards you are mentioning there are too low to talk about CPU and MoBo IO bottlenecks.
You don`t need to worry about your cpu yet.

[turtles123]

thanks karanis!

what card are going to be bottlenecked? just 980 and 1080?

[Liketheriver]

Hi turtles123,

Generally big amount of time between you hit render and the viewport start showing the image, is used for compiling the scene, only a small amount is for send the data to the gpu, large bandwith can help if you do animations with millions of poly, and they are updated every frame (we are talking about few seconds per frame, but in a thousands frame animation they become minutes).

The i5-6600 (or k version) cpu is configurable in pcie 3.0 1x16, 2x8, 1x8+2x4,
If you have two card they are working @ x8 speed, PCIe 3.0 x8 is 16GB/s, is enough for your cards, and also for bigger ones.
If you plan to install 3 card, the rendering process is limited by the speed of the slowest one (x4, 8GB/s) because the render start when all the card are ready.
You can start to think of bandwith if you plan to install 4, 5 or 7 cards and you want all of them in pci 3.0 x8, or with 4 card, x16.

For example, actually I drive 3 gtx 980ti with an i7-2600k @ 4.6ghz (pci-e 2.0 1x8+2x4. half the bandwith of the 6600) of 5 years ago and is more performant than a modern Xeon in scene compiling (less core, more ghz, this is a good thread to read: viewtopic.php?f=9&t=52567&start=20) , the limit with the 6600 (and my 2600k) is if you want to expand your rig, and install 4+ cards, maybe you can buy a mobo with 4 pci slot, and update the cpu with a 40lane when you need it.

[turtles123]

ok got it, i think that processor will be more than enough for everything i am going to do in the next years!

thanks a lot!

[turtles123]

last question!

i know very little about motherboards...

so i found this one https://www.msi.com/Motherboard/Z170A-G ... o-overview
is this a good motherboard? will i be able to une 3 graphic cards with this one? do you have any suggestion?


thanks!!

[karanis]

Forget about processor / mobo thing for now.

It all depends on your projects and the work you are doing.

I am doing 360 jewelry visualisation with Octane. I have 500 models with 8 metal combinations in average and 60 frames to render for each combo, which gives 240,000 frames in final accepted output.
As of my experience, it never goes like that and you render about 3-4 times more frames than you should. That gives about a millon frames.

Now, if you consider 1 second in this case in scene / hardware setup, it means 233 hours for the project.... 1 second timing difference in a frame render costs you about 10 days. Considering "everything went perfect".

I`ve tested and benchmarked many combinations.

So, as my advice, if you are in such low budgets using 70s, the board you`ve selected looks Ok,
do not spend money on cpu, buy the highest gpu that you can.

your selected mobo`s advantage is that, it has a display output so you can leave your cards idle (when you are not using them to lower power consumption)
your selected mobo`s advantage is that, you will not make busy your GPU`s when not they are needed and you`ll get full benefit from them.
your selected mobo`s disadvantage is that, it can only handle 2 pci slots.
your advantage in here is to spend less on cpu

as I said in the beginning :

It all depends on your projects and the work you are doing.

If your loading times are high, use fast disks to read/write, even use your memory as your disk (I`ve installed 64 gigs of old DDR3-1600`s to share 32 as system usage and 32 as RamDisk to load / save frames and when in rendering, I`m transferring from RamDisk to SSD`s and saving (and uploading to req. servers etc.) )

finally,
if you are serious to spend, use Xeon based motherboards (they handle the bus better), buy latest Ti`s, spend on cooling and power supplys, spending money should not be your concern there.
If you are playing with 70`s or dual cards etc, you are loosing your rendering time even reading in here.
Keep it simple

[turtles123]

thanks again for the very detailed answers, i really apreciate that!

so my work is very design oriented, my renders are not very demanding. and i use octane from time to time,

in the last year i did some octane works on a very old pc (i7 920 from 8 years ago!!! ) with 2 graphic cards (770gtx, 960gtx).
i just want to make a little upgrade, and i know i will not need crazy horse power.

i dont understand why i can use just 2 cards on the motherboard i linked earlier. it should have 3x PCIe 3.0 x16 (this means 3 slots for graphic cards right?)

thanks!

[Liketheriver]

Correct, it supports 3, probably because the last is black Karanis missed that, this mobo has the configuration of the mine, the two bottom pci are very close, so when installing three cards, the one in the second slot will fail to dispel the heat if it is not a reference model, i council you to put there an AIO card in this case.

remember, first of all, heat = bad

[smicha]

The mobo https://www.msi.com/Motherboard/Z170A-G ... o-overview
supports up to 3 gpus (dual slotted) provided you get a case with 8 pcie brackets to make use of the lowest socket. Although 2nd and 3rd card will transfer heat to each other.

If I were you I'd get 2x 980ti (400 EUR net today) and sell your slower gpous. Or if have little more budget wait for 1080 performance and support in Octane and better energy savings.