Computer build ready to buy, tips?

Even though the P55 supports both SLI & CF but they are not the best for it.
Crossfire and fast USB3/SATA6Gb are mutually exclusive on the P55A-UD4P. With CF disabled and USB3 or SATA6Gb enabled the first PCIe x16 lane will only work at x8.

With both CF and SATA3 and/or USB3 enabled the the P55 chipset will route some lanes from the x16 to service the SATA3/USB3 controllers so the UD4 will do x8/x8 in Crossfire mode.

In addition the UD4 manual says that if you do have a Crossfire setup at 2x8, SATA3/USB3 will automatically revert to "PCIe Gen 1" mode (250MB/s) so as not to affect the bandwidth of the 2x8 CF setup.


Its may be a bit confusing but it means with crossfire active, both SATA6Gb and USB3 will be constrained to a PCIex1v1 link speeds of 250MB/s. USB3 will show an improvement over USB2, but SATA6Gb won't be any faster than SATA3Gb.

 

well thanks kgtrain, geese im sure thats a feature that not too many people are happy with kinda almost defeats the purpose of getting USB 3.0 and SATA III with this board anyways doesnt it? Also whats the differecne really between running a crossfire in x16 mode or x8 mode. And whats a good board that will pretty much work both Crossfire and Usb/sata 3 without reverting them to the 350mb/s mode you described?

 

2 5770's at x8 is still faster than 1 at x16. PCIe 2.0 x8 is sufficient for current video card generation. Generally speaking, you will not see much (if any) difference between x8 and x16 mode for PCIe 2.0. The Radeon HD 5770 performance level drops only by 2% overall when split into two 8 lane links. Even at PCIe x1, leaving only 1/16th of the optimum bandwidth it can still deliver 75% of its performance.

The performance penalty between two PCIe 2.0 x16 (electrical x8) and PCIe 2.0 x16 (electrical x16) is negligible unless every frame per second increase matters to you. There is no reason to worry about a performance drop on mid-range motherboards.

A direct quote from Gigabyte...

If you want to keep the costs down go for the cheaper option, if two 5770's are cheaper than one 5850 choose that. Otherwise (as more bandwidth is always better) get the single more powerfull 5850.

As for USB 3 and SATA Rev 3, only if your getting a SSD is it worth it. At the moment a single HDD cant even saturate SATA 2 (3GB/s) bandwidth yet. USB 3 would be nice for burst speeds but they wont be able to take full advantage of this for some time.

 

Trancer: Not exactly, USB3 and S-ATA 3 will still work but they will have less bandwidth between them, because when you use both of the PCI Express slots, there is too little bandwidth available to the system to give all of the ports their full speed. If you only use one of them, you probably won't notice any drop in performance, especially not with USB3, as even when crippled, USB3 is miles faster than USB2 (S-ATA3 is only twice the speed of S-ATA2 but USB3 is 10 times as fast as USB2)
I always leave USB3 and S-ATA 3 in normal mode because I don't have any USB3 or S-ATA3 devices yet, and even if I did, S-ATA 3 is a bit of a waste of time because nothing is really fast enough to use it yet. That, and I also use both my 16x ports for Crossfire.


The lack of bandwidth is nothing to do with Gigabyte, it is a limitation of LGA1156. The PCI express is provided by the CPU and not the board, and the CPU can only produce 16x bandwidth, so it has to be shared out.

PCI Express at 16x versus PCI Express at 8x has only a 2% effect on performance, it's negligible, you'll never notice it.
Even the fastest SSDs can only continuously use bandwidth around 250MB/s, and S-ATA 2 allows 375MB/s, so you've no reason to use S-ATA 3 yet at all, and even in PCIe1.0 mode at 250MB/s, USB3 still has 250MB/s to play with, which is actually enough to pretty much max the technology out anyway, given how USB bandwidth works.
Ultimately, even with a crossfire setup, running USB3 and S-ATA3 in normal mode, you are never going to notice the difference for a long time to come.

 

Yea I know its not Gigabytes fault. They have much more credit than me when it comes to the I.T world so I used a quote from them showing it doesnt make a difference running at x8 or x16.
Np tho, I'm pretty easy to misinterpret

 

Thanks guys, you're both a major help! Probably for the best I haven't been paid yet and had time to keep asking questions, otherwise I would have just jumped right in and bought something XD I'll be back again if I need anything (Y)

 

Well I just realised that a new build of mine is almost identical to yours, maybe we can help eachother lol

Have a look if you want.
http://forums.afterdawn.com/t.cfm/f-216/new_i5_build_thoughts_criticisms-846583/

 

Alright so I crunched some more numbers and decided I could probably pay a little more for this thing, so let me know what you think?

CPU: Intel i5 750
MOBO: Gigabyte GA-P55A-UD7
GPU: XFX HD 587X (5870)
PSU: Corsair 650TX (it's on sale at new-egg right now)
RAM: 4GB Corsair XMS3 1600MHz
HDD: WD Cavier Black AAEX 640GB Sata III
Optical: Sony Optiarc 24x DVD/CD
Case: Coolermaster RC 690

That brings me to about $1 500 at newegg and gets me some very decent stuff , monitor will come later, along with CPU cooler and prolly some case mods down the road (Y)

 

I would only consider the UD7 if you were to looking for the top-end LGA1156 mobo or will Crossfire, otherwise its overkill and theres no need. Save on that and get a UD3 or UD4 tops. The main difference between the three boards is the UD7 supports both Nvidia NF200 and PEX 8608 PCI-E bridge controllers. This means that it is not limited by the platforms PCI-E configuration and supports 'three-way Crossfire' features not normally supported on the socket 1156 platform.

Also theres no point with SATA 3 unless its SSD. Think of it as a speed limit. Just because the sign says 300mph, that doesnt mean you can do it! SATA 3 will not be any faster then SATA 2 on a HDD, they can not physically spin that fast. At the moment theres not one single HDD can even fill SATA 2 (3GB/s) bandwidth. Get a WD Caviar Black 1TB SATA II @ 7200 rpm.

 

I agree, the P55A-UD7 is total overkill, I'd consider that I went for a higher end build than the one here and I only chose the P55A-UD4.
You also don't need the S-ATA3 drive, S-ATA3 on mechanical drives is a bit of a con, it doesn't achieve anything. For the same price as the 750GB S-ATA3 drive, you can probably get a WD1001FALS.
As kg says, the only thing that sets the P55A-UD7 apart from other high end P55 boards is the use of PCI express boosters that provide extra bandwidth. We've already shown what a negligible effect that has in crossfire, and it of course has no benefit at all with the use of a single card.
The same issue about 8x stands for 4x. Even with 4x bandwidth a card only drops performance by 5%, making the use of an extra card beyond two still perfectly viable, even without bandwidth boosters. The best way to do triple graphics seems to be to use a dual card and a single card, for example, a 5970 and a 5850 alongside. I'm hoping to combine an HD5970 4GB LE with an HD5870 2GB Eyefinity6 card at some point.

 

k no UD7 will stick with UD4 ha ha ha. Just wondering what would be a good CPU cooler/heatsink to use to overclock?

For using the CM 690 anyways?

 

Noctua NH-U12P.

 

XD thats almost 100 bucks, something under $50? Suppose I should have specified lol.

 

Try the Cool Master Hyper 212 Plus then its $35, it cheaper but not as good as the Noctua NH-U12P.
http://www.newegg.com/Product/Produ...03065&cm_re=Hyper_212+-_-35-103-065-_-Product

 

If $75 is almost $100, fair enough.
The 212 plus is very weak for how much it costs. You're better off with a Xigmatek S983 if you're willing to spend only $35.
If you can spend $50, then get the Noctua NH-U9.