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Does 3930K support PCI-E 3.0 x16 properly?

Krzych

Hi,

I am planning to buy X79 platform with 3930K (4930K very hard to find in my country) but I just read something about Sandy Bridge-E not supporting PCI-E 3.0 natively and people having issues. I plan to run GTX 1080 SLI on it and I don't want to pay for X99 platform with 40-lane CPU that would cost me 5 times more that used X79+3930K.

Whole point of going for this platform is being able to run those cards at x16/x16 PCI-E 3.0 and now I see that it may not work...

There are quite a mixed reports on that, what's the truth?

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I have one, as you can see, yes it runs it properly, at least for me, running 970 sli. Even if it was 2.0 there would be no noticeable bottleneck.

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PCIe 3.0 was introduced with Ivy Bridge. It didn't exist in earlier architectures. Your cards should work, but they will be running in PCIe 2.0 16x/16x. As said above, it should be fine.

 

In terms of bandwidth, I believe that's equal to PCIe 3.0 8x/8x, which is an extremely common way to do SLI.

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6 minutes ago, Krzych said:

Hi,

I am planning to buy X79 platform with 3930K (4930K very hard to find in my country) but I just read something about Sandy Bridge-E not supporting PCI-E 3.0 natively and people having issues. I plan to run GTX 1080 SLI on it and I don't want to pay for X99 platform with 40-lane CPU that would cost me 5 times more that used X79+3930K.

Whole point of going for this platform is being able to run those cards at x16/x16 PCI-E 3.0 and now I see that it may not work...

There are quite a mixed reports on that, what's the truth?

Where did you find a X79 motherboard? I would get a x79 chip instead of a 4770 but h81 is easy to find and i cant find x79?

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24 minutes ago, Ashiella said:

I have one, as you can see, yes it runs it properly, at least for me, running 970 sli. Even if it was 2.0 there would be no noticeable bottleneck.

 

23 minutes ago, typographie said:

PCIe 3.0 was introduced with Ivy Bridge. It didn't exist in earlier architectures. Your cards should work, but they will be running in PCIe 2.0 16x/16x. As said above, it should be fine.

 

In terms of bandwidth, I believe that's equal to PCIe 3.0 8x/8x, which is an extremely common way to do SLI.

Unfortunately this is not true and even PCI-E 3.0 x8/x8 bottlenecks SLI significantly, and thats only for 980 Ti or Titans, 1080s are even faster. I would just upgrade to 4790K or 5775C if PCI-E bandwidth wasn't an issue, this is what I planned to do originally. Here:

 

21 minutes ago, Ethan Meskin said:

Where did you find a X79 motherboard? I would get a x79 chip instead of a 4770 but h81 is easy to find and i cant find x79?

In Poland I found only one on sale in entire country, didn't bought yet. But there are quite a lot of them on German and British ebay. Not muich cheaper than X99 boards unfortunately, but 2011 CPUs are way, way cheaper than 2011-v3. Like 4 times.

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CPU: i7-6900K 4.5 GHz | Motherboard: X99 Sabertooth | GPU: RTX 2080 Ti SLi | RAM: 32GB DDR4-3400 CL13 | SSD: SX8200 PRO 512GB | PSU: Corsair AX1600i | Case: InWin 805C | Monitor: LG 38UC99-W 85Hz | Keyboard: Wooting One Analog | Keypad: Azeron Compact Analog | Mouse: Swiftpoint Z | Audio: Klipsch Reference 5.1

 

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12 minutes ago, Krzych said:

 

Unfortunately this is not true and even PCI-E 3.0 x8/x8 bottlenecks SLI significantly, and thats only for 980 Ti or Titans, 1080s are even faster. I would just upgrade to 4790K or 5775C if PCI-E bandwidth wasn't an issue, this is what I planned to do originally. Here:

 

In Poland I found only one on sale in entire country, didn't bought yet. But there are quite a lot of them on German and British ebay. Not muich cheaper than X99 boards unfortunately, but 2011 CPUs are way, way cheaper than 2011-v3. Like 4 times.

Where exactly did you find the information that 3.0 8x/8x will bottleneck a 980ti/Titan X? Because It doesn't. With a 980ti sli PCIE 3.0 8x/8x it's a 2-5 fps drop at 1080p, its completely unnoticeable.

Specs v-v

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Cpu: Ryzen 9 3900x @ 1.1v / Motherboard: Asus Prime X570-P / Ram: 32GB 3000Mhz 16-16-16-36 Team Vulcan (4x8GB) / Storage: 1x 1TB Lite-on EP2, 2x 128GB PM851 SSD, 3x 1TB WD Blues / Gpu: GTX Titan X (Pascal) / Case: Corsair 400c Carbide / Psu: Corsair RMi 750w / OS: Windows 10

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5 minutes ago, Krzych said:

In Poland I found only one on sale in entire country, didn't bought yet. But there are quite a lot of them on German and British ebay. Not muich cheaper than X99 boards unfortunately, but 2011 CPUs are way, way cheaper than 2011-v3. Like 4 times.

Ah, I'll stick with the 4770 and h81 unless i can get a x79 cpu, mobo and cooler for less than £200

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1 minute ago, Ashiella said:

Where exactly did you find the information that 3.0 8x/8x will bottleneck a 980ti/Titan X? Because It doesn't. With a 980ti sli PCIE 3.0 8x/8x it's a 2-5 fps drop at 1080p, its completely unnoticeable.

 I have included two videos in previous post.

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CPU: i7-6900K 4.5 GHz | Motherboard: X99 Sabertooth | GPU: RTX 2080 Ti SLi | RAM: 32GB DDR4-3400 CL13 | SSD: SX8200 PRO 512GB | PSU: Corsair AX1600i | Case: InWin 805C | Monitor: LG 38UC99-W 85Hz | Keyboard: Wooting One Analog | Keypad: Azeron Compact Analog | Mouse: Swiftpoint Z | Audio: Klipsch Reference 5.1

 

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1 minute ago, Krzych said:

 I have included two videos in previous post.

Ya know that time when you duno how to talk to people? For example: My teacher was strobing a flashlight and a classmate said: That could cause a seizure. Me: So, it could trigger Epilepsy. Classmate: Thats what I said, its the same thing.

 

I didn't know how to talk to him henceforth. Same kind of thing with you. You should try being more open, you wouldnt be asking for help on this forum otherwise. I'm fairly certain that 90% of LTT will agree with me.

Specs v-v

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Cpu: Ryzen 9 3900x @ 1.1v / Motherboard: Asus Prime X570-P / Ram: 32GB 3000Mhz 16-16-16-36 Team Vulcan (4x8GB) / Storage: 1x 1TB Lite-on EP2, 2x 128GB PM851 SSD, 3x 1TB WD Blues / Gpu: GTX Titan X (Pascal) / Case: Corsair 400c Carbide / Psu: Corsair RMi 750w / OS: Windows 10

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3 minutes ago, Ethan Meskin said:

Ah, I'll stick with the 4770 and h81 unless i can get a x79 cpu, mobo and cooler for less than £200

I have seen people getting X79 + CPU really cheap, especially if you don't need 40 lanes then 3820K costs like next to nothing, less than new i3s in shops. 

5 minutes ago, Ashiella said:

Ya know that time when you duno how to talk to people? For example: My teacher was strobing a flashlight and a classmate said: That could cause a seizure. Me: So, it could trigger Epilepsy. Classmate: Thats what I said, its the same thing.

 

I didn't know how to talk to him henceforth. Same kind of thing with you. You should try being more open, you wouldnt be asking for help on this forum otherwise. I'm fairly certain that 90% of LTT will agree with me.

I don't really understand what you are saying. I said something that I knew is controversial so I included two videos for proof, I don't really understand what more would you need or want.

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10 minutes ago, Krzych said:

I have seen people getting X79 + CPU really cheap, especially if you don't need 40 lanes then 3820K costs like next to nothing, less than new i3s in shops. 

I don't really understand what you are saying. I said something that I knew is controversial so I included two videos for proof, I don't really understand what more would you need or want.

There is no K sku of the 3820.

That your sources are likely false.

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Cpu: Ryzen 9 3900x @ 1.1v / Motherboard: Asus Prime X570-P / Ram: 32GB 3000Mhz 16-16-16-36 Team Vulcan (4x8GB) / Storage: 1x 1TB Lite-on EP2, 2x 128GB PM851 SSD, 3x 1TB WD Blues / Gpu: GTX Titan X (Pascal) / Case: Corsair 400c Carbide / Psu: Corsair RMi 750w / OS: Windows 10

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17 minutes ago, Ashiella said:

There is no K sku of the 3820.

That your sources are likely false.

Thats just the typo because of being used to write 5820k :) And yea, benchmarks made in co-op with overclocker ExtremeAddict are certainly not a reliable source. You and your repeating of myths that you heard somewhere without actually testing, this is reliable source :D You know, I don't believe in God, but still God save the man that will have to deal with you, just in case :P Don't bother replying, because you will be talking to the air and it doesn't deserve that for what it does for us ;) 

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CPU: i7-6900K 4.5 GHz | Motherboard: X99 Sabertooth | GPU: RTX 2080 Ti SLi | RAM: 32GB DDR4-3400 CL13 | SSD: SX8200 PRO 512GB | PSU: Corsair AX1600i | Case: InWin 805C | Monitor: LG 38UC99-W 85Hz | Keyboard: Wooting One Analog | Keypad: Azeron Compact Analog | Mouse: Swiftpoint Z | Audio: Klipsch Reference 5.1

 

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You will not notice any difference between PCIe 3.0 x8/x8 and PCIe 3.0 x16/x16.  I own an x99/5960x platform and a z270/7700k platfor.  The 5960x obviously runs x16/x16, while the 7700k runs x8/x8.  There is no difference.  On the rare occasion when benchmarks/games become CPU dependent, the 7700k will usually beat out the 5960x despite it having a supposed x16/x16 advantage.  This exclude benchmarks/games which are optimized for more threads, but those are so far and few between, they're really not a talking point at this point in time.

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12 minutes ago, Krzych said:

Thats just the typo because of being used to write 5820k :) And yea, benchmarks made in co-op with overclocker ExtremeAddict are certainly not a reliable source. You and your repeating of myths that you heard somewhere without actually testing, this is reliable source :D You know, I don't believe in God, but still God save the man that will have to deal with you, just in case :P Don't bother replying, because you will be talking to the air and it doesn't deserve that for what it does for us ;) 

Although you said don't bother replying. Linus himself did a video on this and 8x/8x has minimal degradation compared to 16x/16x. @Rika Shiguma this guy is a retard. I don't even care if I'm striked.

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Cpu: Ryzen 9 3900x @ 1.1v / Motherboard: Asus Prime X570-P / Ram: 32GB 3000Mhz 16-16-16-36 Team Vulcan (4x8GB) / Storage: 1x 1TB Lite-on EP2, 2x 128GB PM851 SSD, 3x 1TB WD Blues / Gpu: GTX Titan X (Pascal) / Case: Corsair 400c Carbide / Psu: Corsair RMi 750w / OS: Windows 10

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3 minutes ago, done12many2 said:

You will not notice any difference between PCIe 3.0 x8/x8 and PCIe 3.0 x16/x16.  I own an x99/5960x platform and a z270/7700k platfor.  The 5960x obviously runs x16/x16, while the 7700k runs x8/x8.  There is no difference.  On the rare occasion when benchmarks/games become CPU dependent, the 7700k will usually beat out the 5960x despite it having a supposed x16/x16 advantage.  This exclude benchmarks/games which are optimized for more threads, but those are so far and few between, they're really not a talking point at this point in time.

Yeah Linus did a video on it, and this guy doesn't believe me. He also thinks that the x79 doesn't run in 3.0 with the 3930k, I have one. I would know that it does.

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Cpu: Ryzen 9 3900x @ 1.1v / Motherboard: Asus Prime X570-P / Ram: 32GB 3000Mhz 16-16-16-36 Team Vulcan (4x8GB) / Storage: 1x 1TB Lite-on EP2, 2x 128GB PM851 SSD, 3x 1TB WD Blues / Gpu: GTX Titan X (Pascal) / Case: Corsair 400c Carbide / Psu: Corsair RMi 750w / OS: Windows 10

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2 minutes ago, Ashiella said:

Yeah Linus did a video on it, and this guy doesn't believe me. He also thinks that the x79 doesn't run in 3.0 with the 3930k, I have one. I would know that it does.

 

Some people believe everything they watch in a YouTube video.  There's so much misinformation out there, that you can find 10 videos/articles to support any side of any debate.  I'd rather learn things for myself and in this case, x16 vs x8 is so negligible that often times any difference fall within the margin of error for the testing itself. 

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SB-e C1 silicon has apparently a hardware bug that may show up when running in PCI-e 3.0 (2.0 is OK) [BSOD, stability issues, etc.].
SB-e C2 silicon has that bug fixed (along with VT-d support), and should work fine in PCI-e 3.0 mode.

I use driver mod to enable PCI-e 3.0 on my GTX 780 Ti with i7 3820 CPU (both work fine together, but I have C2 revision of CPU chip).

CPU : Core i7 6950X @ 4.26 GHz + Hydronaut + TRVX + 2x Delta 38mm PWM
MB : Gigabyte X99 SOC (BIOS F23c)
RAM : 4x Patriot Viper Steel 4000MHz CL16 @ 3042MHz CL12.12.12.24 CR2T @1.48V.
GPU : Titan Xp Collector's Edition (Empire)
M.2/HDD : Samsung SM961 256GB (NVMe/OS) + + 3x HGST Ultrastar 7K6000 6TB
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12 hours ago, Ashiella said:

Although you said don't bother replying. Linus himself did a video on this and 8x/8x has minimal degradation compared to 16x/16x. @Rika Shiguma this guy is a retard. I don't even care if I'm striked.

Don't know why you tagged me. You could've just told me in pms/steam or smthn lol

Ryzen 5 3600

RX 590 8GB 

WD Blue 1TB

(full specs on profile)

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30 minutes ago, Rika Shiguma said:

Don't know why you tagged me. You could've just told me in pms/steam or smthn lol

Shush.

Specs v-v

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Cpu: Ryzen 9 3900x @ 1.1v / Motherboard: Asus Prime X570-P / Ram: 32GB 3000Mhz 16-16-16-36 Team Vulcan (4x8GB) / Storage: 1x 1TB Lite-on EP2, 2x 128GB PM851 SSD, 3x 1TB WD Blues / Gpu: GTX Titan X (Pascal) / Case: Corsair 400c Carbide / Psu: Corsair RMi 750w / OS: Windows 10

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I ended up with 4820K. And thats good because my power supply wouldn't manage overclocked 3930K with two overclocked cards. With 4820K 4.7 GHz 1.41 V and overclocked GPUs I am around 715 W peak in Time Spy on 750 W power supply, so pretty close. Games don't draw that much but still I will use a bit tighter power limits on them or just decrease clocks a bit. 4820K was also much cheaper, around the price of new FX-8350, so that's like nothing for such CPU. 

 

As for PCI-E lanes, I am not going to read this thread from where I stopped following, there is no point in that now, but for now I just made one test in Witcher 3, Ultra without Hairworks, 3440x1440, location is Crookback Bog so no affect from CPU side:

 

2.0 x16/x16 - 73 AVG 68 MIN

3.0 x8/x8 - 87 AVG 79 MIN

3.0 x16/x16 - 93 AVG 86 MIN

 

 

 

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CPU: i7-6900K 4.5 GHz | Motherboard: X99 Sabertooth | GPU: RTX 2080 Ti SLi | RAM: 32GB DDR4-3400 CL13 | SSD: SX8200 PRO 512GB | PSU: Corsair AX1600i | Case: InWin 805C | Monitor: LG 38UC99-W 85Hz | Keyboard: Wooting One Analog | Keypad: Azeron Compact Analog | Mouse: Swiftpoint Z | Audio: Klipsch Reference 5.1

 

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  • 1 month later...

Just in case someone comes across this thread when looking for the same answer, here is proper answer from Nvidia website:

Quote

 

GeForce GTX 600 series (Kepler class) and higher GPUs support PCI Express 3.0. They operate properly within the SIG PCI Express Specification and have been validated on multiple PCI Express 3.0 platforms. Some motherboard manufacturers have released an updated SBIOS to enable the Intel X79/SNB-E PCI Express 2.0 platform to run at up to 8GT/s bus speeds. We have tested GeForce GTX 680 and GTX 670 GPUs across a number of X79/SNB-E platforms at 8GT/s bus speeds, but have seen significant variation in signal timing across different motherboards and CPUs. Therefore we’ve decided to only support and guarantee PCI Express 2.0 bus speeds on X79/SNB-E with our standard release drivers. Native PCI Express 3.0 platforms (like Ivy Bridge) will run at 8GT/s bus speeds with our standard release drivers. 

Though we cannot officially support or guarantee 8GT/s speeds for X79/SNB-E, you can manually enable faster 8GT/s bus speeds (at your own risk) using the following executable: force-enable-gen3.exe

If you would like to revert back to 5GT/s bus speeds you can do so by running the following command from the DOS command line: “force-enable-gen3.exe –revert”

You may download "force-enable-gen3.exe" from the File Attachments section below.  You will need to reboot your system for the changes to take effect.

https://nvidia.custhelp.com/app/answers/detail/a_id/3135/~/geforce-gen3-support-on-x79-platform

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CPU: i7-6900K 4.5 GHz | Motherboard: X99 Sabertooth | GPU: RTX 2080 Ti SLi | RAM: 32GB DDR4-3400 CL13 | SSD: SX8200 PRO 512GB | PSU: Corsair AX1600i | Case: InWin 805C | Monitor: LG 38UC99-W 85Hz | Keyboard: Wooting One Analog | Keypad: Azeron Compact Analog | Mouse: Swiftpoint Z | Audio: Klipsch Reference 5.1

 

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