Intel i7-3770K Ivy Bridge vs. i7-3820 Sandy Bridge-E for scientific computing

[officerping]

Hi there,

I'm trying to decide between two workstation builds:
https://dl.dropbox.com/u/5381783/build.pdf
https://dl.dropbox.com/u/5381783/build2.pdf

The components are all the same, except for the motherboard and CPU. One is the i7-3770K, an Ivy Bridge processor; the other is the i7-3820, a Sandy Bridge-E processor.

A few components are missing (power supply, storage HD, video card) because I plan on salvaging them from existing boxes. I have two GTX 480's and a GTX 470 that I plan to install, but in the future we might upgrade them to GTX 680 or whatever comes out in the future.

My application is scientific computing. I need this box to do two things mainly:
1) Rapid execution of single-threaded processes on the CPU 2) High bandwidth and low latency for communication between the CPU and GPU
From what I've heard, the i7-3770K (Ivy Bridge) has the following advantages:
1) More rapid single thread execution by 10-20%.
2) Supports PCI-e 3.0, whereas Sandy Bridge doesn't (?) I've gotten conflicting evidence over this: (http://www.anandtech.com/show/5264/sandy-bridge-e-x79-pcie-30-it-works). Only the newest graphics cards support PCI-e 3.0, so this pertains to upgradeability and not the present GPUs.
3) Supports USB 3.0 whereas Sandy Bridge-E does not? This isn't a primary requirement, but since this is a workstation, rapid data transfer to external drives is a big plus.
4) Smaller transistors are "cooler"

The i7-3280 (Sandy Bridge-E) has the following advantages:
1) More memory bandwidth (quad channel, vs. dual channel for Ivy Bridge)
2) More PCI-E lanes for greater GPU/CPU communication bandwidth (40 lanes, vs. 16 for Ivy Bridge)

I'm leaning towards the Sandy Bridge-E processor because of the greater bandwidth. Some people say I don't need 40 PCI-E lanes with two GTX 480 cards - however, scientific computing applications can require very high data throughput (I don't know how to measure exactly how high) and it would be great to have a machine where bandwidth is not an issue. I think this is potentially more important than the performance boost on single thread execution that I'd get from the Ivy Bridge.

Overclocking is a minor concern. I've never overclocked any CPU (even though I've assembled 20+ boxes over the years), and when it comes to work-related hardware I am relatively risk-averse. That said, if one of the CPU can be more easily overclocked by a minor amount, it might affect my decision.

I welcome any comments about other components of my build, but I'm a fan of Antec cases and Zalman fans, so I'm less likely to be swayed on my case / fan choice for better or worse.

Thanks for reading!

 

[HendrixFan]

If you have a microcenter nearby, the 3820 is considerably cheaper than the 3770k, if price is a factor.

 

[officerping]

Thank you for the reply. I need to order online through my work. The LGA 2011 socket motherboard for the i7-3820 tends to be more expensive, so I find that the prices are comparable.

 

[exar333]

I would seriously suggest dropping the Zalman cooler and getting the 3930k CPU instead. Get a cheap CM 212+ cooler and you can still OC if you want. The extra cores would go a long way on the 2011 platform for not a lot more $$$.

 

[officerping]

I would seriously suggest dropping the Zalman cooler and getting the 3930k CPU instead. Get a cheap CM 212+ cooler and you can still OC if you want. The extra cores would go a long way on the 2011 platform for not a lot more $$$.

I'm concerned that the lower clock speed on the 3930K CPU would result in lower single thread performance (although i would benefit when running parallel tasks). If the single thread performance is comparable then I could justify spending the extra money.

 

[Smoblikat]

I would seriously suggest dropping the Zalman cooler and getting the 3930k CPU instead. Get a cheap CM 212+ cooler and you can still OC if you want. The extra cores would go a long way on the 2011 platform for not a lot more $$$.

Isnt a 3930K like 600$, a 3770K/3820 is like 300$. Thats a 100% increase, hardly minimal.

 

[officerping]

I should add that I can run highly parallel tasks on a cluster (a good cluster would have 40 dual Xeon X5650 boxes shared between 10 users). That decreases the incentive of getting a 6-core CPU for this workstation.

 

[exar333]

Isnt a 3930K like 600$, a 3770K/3820 is like 300$. Thats a 100% increase, hardly minimal.

A few hundred for a actual workstation is not a lot of $$$ if it's worth it. This isn't for a hobby/gaming box.

 

[exar333]

I should add that I can run highly parallel tasks on a cluster (a good cluster would have 40 dual Xeon X5650 boxes shared between 10 users). That decreases the incentive of getting a 6-core CPU for this workstation.

I was going to ask if more cores would help or not. Based on this, your probably good with 4 cores. S2011 will be great though, because you will have an option to go more cores, if that helps down the road.

 

[bunnyfubbles]

From what I've heard, the i7-3770K (Ivy Bridge) has the following advantages:
1) More rapid single thread execution by 10-20%.

that seems a little high unless you actually looked up a performance comparison for software yous specifically care about, otherwise the IPC performance advantage is closer to ~5%

2) Supports PCI-e 3.0, whereas Sandy Bridge doesn't (?) I've gotten conflicting evidence over this: (http://www.anandtech.com/show/5264/sandy-bridge-e-x79-pcie-30-it-works). Only the newest graphics cards support PCI-e 3.0, so this pertains to upgradeability and not the present GPUs.

SandyBridge does not support PCI-e 3.0, however X79 and SandyBridge E are PCI-e 3.0 ready. It would be up to the motherboard model/manufacturer to make sure the feature is enabled, IIRC.

3) Supports USB 3.0 whereas Sandy Bridge-E does not? This isn't a primary requirement, but since this is a workstation, rapid data transfer to external drives is a big plus.

The primary difference is that Intel just started producing a USB3.0 controller of their own on their newest 7 series chipsets for IvyBridge and have yet to do the same for X79 and SandyBridge-E on socket 2011. However just about all motherboards since way back with the first generation i7s have included 3rd party USB3.0 controllers, so I would be shocked if your chosen X79 motherboard did not include support for USB3.0. Performance difference should be negligible, the advantage being mostly convenience and intel's reputation for reliability.

4) Smaller transistors are "cooler"

Ivy will certainly put out less heat, but the CPU won't necessarily run at a lower temperature which will hurt its max potential when overclocking

The i7-3280 (Sandy Bridge-E) has the following advantages:
1) More memory bandwidth (quad channel, vs. dual channel for Ivy Bridge)

Keep in mind its not necessarily just extra memory bandwidth, but extra capacity, many s2011 motherboards have up to 8 slots, which makes it that much easier to have double the memory capacity of a s1155 motheboard

2) More PCI-E lanes for greater GPU/CPU communication bandwidth (40 lanes, vs. 16 for Ivy Bridge)

This can be the other significant advantage of X79

However the 3rd advantage of going X79/s2011 that you didn't seem to consider would be future CPU upgradability. With a new 3770K Z77 rig, you would pretty much be at a dead end, which would not be the case if you go with an i7 3820. And while recent news suggest X79 will support future IvyBridge-E CPUs (which could potentially offer up to 8+ cores), even if that doesn't turn out to be the case you can always drop in a 6 core SB-E CPU later on.

I'm leaning towards the Sandy Bridge-E processor because of the greater bandwidth. Some people say I don't need 40 PCI-E lanes with two GTX 480 cards - however, scientific computing applications can require very high data throughput (I don't know how to measure exactly how high) and it would be great to have a machine where bandwidth is not an issue. I think this is potentially more important than the performance boost on single thread execution that I'd get from the Ivy Bridge.

While running two 480s on a 3770K vs. a 3820 might not net much of a difference (of which it very well might), with the 3820 you'd still have plenty of PCI-e lanes to spare should you want to add any extra cards later on (be it another GPU or perhaps storage controller or something else entirely)

Overclocking is a minor concern. I've never overclocked any CPU (even though I've assembled 20+ boxes over the years), and when it comes to work-related hardware I am relatively risk-averse. That said, if one of the CPU can be more easily overclocked by a minor amount, it might affect my decision.

The 3770K is technically "easier" to overclock as it has an unlocked multiplier, however keeping its operating temperatures in check would offset things a bit. And while the 3820 has a locked multiplier, SB-E allows for some flexibility in more traditional FSB overclocking. A simple change from 100 to 125 would net a relatively easy 4.5GHz on the 3820 if you can find the volts to match as well as keep temps in check, which wouldn't be that hard to do compared to a 3770K.

granted, as someone else has mentioned the 3930K, that CPU as an option for s2011 and would be just as "easy" to overclock as it has an unlocked multiplier just like the 3770K

 

[Sunny129]

what kind of scientific computing are you talking about? is it for professional/work applications, or are you building a DC machine?

 

[dinker99]

The 3770K is technically "easier" to overclock as it has an unlocked multiplier, however keep its operating temperatures in check might offset things. And while the 3820 has a locked multiplier, SB-E allows for some flexibility in more traditional FSB overclocking. A simple change from 100 to 125 would net a relatively easy 4.5GHz if you can find the volts to match as well as keep temps in check, which wouldn't be that hard to do compared to a 3770K.

I`m typing this on an Asus P9X79 PRO with a 3820, the only thing I needed to do to get 4.5GHz was to change the strap to 125

 

[officerping]

I was going to ask if more cores would help or not. Based on this, your probably good with 4 cores. S2011 will be great though, because you will have an option to go more cores, if that helps down the road.

Agreed. I know $200 is not much of a price increase for a workstation, but for this particular one I am on a budget. Thanks.

 

[officerping]

what kind of scientific computing are you talking about? is it for professional/work applications, or are you building a DC machine?

This is for my research in molecular dynamics simulation. I wrote a software for force field optimization that interfaces with several GPU and CPU codes. What is a "DC machine"?

 

[officerping]

I`m typing this on an Asus P9X79 PRO with a 3820, the only thing I needed to do to get 4.5GHz was to change the strap to 125

That sounds great. What fan / heatsink are you using? I've never used liquid cooling but I heard it could be helpful for these things.

 

[exar333]

The NH-D14 is a monster air cooler for the 2011 platform and can be very quiet. The CM 212+ is a great budget cooler to get you easily to 4.0-4.3ghz.

Edit: The Noctua will still cool a 6 or even 8-core cpu down the road, if you decide to drop it in).

 

[officerping]

that seems a little high unless you actually looked up a performance comparison for software yous specifically care about, otherwise the IPC performance advantage is closer to ~5%

I was looking at AnandTech's own benchmark suite. I don't know what the performance would be for my specific simulation software.

SandyBridge does not support PCI-e 3.0, however X79 and SandyBridge E are PCI-e 3.0 ready. It would be up to the motherboard model/manufacturer to make sure the feature is enabled, IIRC.

I see. I'll make sure to get a motherboard that supports PCI-e 3.0.

The primary difference is that Intel just started producing a USB3.0 controller of their own on their newest 7 series chipsets for IvyBridge and have yet to do the same for X79 and SandyBridge-E on socket 2011. However just about all motherboards since way back with the first generation i7s have included 3rd party USB3.0 controllers, so I would be shocked if your chosen X79 motherboard did not include support for USB3.0. Performance difference should be negligible, the advantage being mostly convenience and intel's reputation for reliability.

Can you clarify why USB3.0 support can come from either the motherboard or the CPU? I'm a bit confused here.

Ivy will certainly put out less heat, but the CPU won't necessarily run at a lower temperature which will hurt its max potential when overclocking

I meant that smaller transistors was "cooler" in a nerdy way.

Keep in mind its not necessarily just extra memory bandwidth, but extra capacity, many s2011 motherboards have up to 8 slots, which makes it that much easier to have double the memory capacity of a s1155 motheboard

I'm going for 32 GB (4x8GB). Using this size of memory module, it appears that my chosen motherboard could go up to 64 GB. This is helpful for certain applications, but for very memory intensive applications, the "large memory" nodes can reach 512 GB or more.

However the 3rd advantage of going X79/s2011 that you didn't seem to consider would be future CPU upgradability. With a new 3770K Z77 rig, you would pretty much be at a dead end, which would not be the case if you go with an i7 3820. And while recent news suggest X79 will support future IvyBridge-E CPUs (which could potentially offer up to 8+ cores), even if that doesn't turn out to be the case you can always drop in a 6 core SB-E CPU later on.

That is a good point. It sounds like s2011 is much better in terms of upgradeability, which could increase the lifespan of this box.

While running two 480s on a 3770K vs. a 3820 might not net much of a difference (of which it very well might), with the 3820 you'd still have plenty of PCI-e lanes to spare should you want to add any extra cards later on (be it another GPU or perhaps storage controller or something else entirely)

Definitely. I might add a third GPU at some point, or upgrade the existing ones.

The 3770K is technically "easier" to overclock as it has an unlocked multiplier, however keeping its operating temperatures in check would offset things a bit. And while the 3820 has a locked multiplier, SB-E allows for some flexibility in more traditional FSB overclocking. A simple change from 100 to 125 would net a relatively easy 4.5GHz on the 3820 if you can find the volts to match as well as keep temps in check, which wouldn't be that hard to do compared to a 3770K.

I'll look into the BIOS. What number is changing from 100 to 125 precisely? I'm completely new when it comes to overclocking, so I don't know the distinction between the FSB and multiplier.

granted, as someone else has mentioned the 3930K, that CPU as an option for s2011 and would be just as "easy" to overclock as it has an unlocked multiplier just like the 3770K

The main advantage of the 3930K is two more cores. I'm still considering it, but it's kind of a minor option.

Thanks!

 

[officerping]

The NH-D14 is a monster air cooler for the 2011 platform and can be very quiet. The CM 212+ is a great budget cooler to get you easily to 4.0-4.3ghz.

Edit: The Noctua will still cool a 6 or even 8-core cpu down the road, if you decide to drop it in).

Wow, that is a pretty amazing-looking cooler. I'm definitely considering this as an option. Is the cooler size ever an issue?

I've installed several Zalman CNPS9500 / 9700 coolers over the years, and due to their size I need to install the CPU and cooler when the motherboard is still outside the case.

 

[Sunny129]

This is for my research in molecular dynamics simulation. I wrote a software for force field optimization that interfaces with several GPU and CPU codes. What is a "DC machine"?

DC = distributed computing (the type of scientific computing projects that require supercomputer power but can't afford supercomputers, so they fragment the work and distribute it millions of participants who volunteer their personal computer's spare CPU & GPU cycles to crunch the work).

i just wanted to confirm whether or not that was what you were trying to do, b/c factors like memory capacity and bandwidth, PCIe 2.0 vs 3.0, PCIe x16 vs x8 vs x4, etc., are all highly dependent upon which DC project(s) you choose to participate in...but since you're not doing DC, you needn't be worried about those things.

 

[officerping]

I see. Yes, I'm familiar with distributed computing and my current research group founded one of these projects (Folding@Home). Thanks for your donations, they've been incredibly helpful for scientific research.

 

[Sunny129]

Can you clarify why USB3.0 support can come from either the motherboard or the CPU? I'm a bit confused here.

its not the CPU itself that provides the support - its either the motherboard chipset or a 3rd party chip that provides USB 3.0 support. in other words, if the motherboard's chipset supports USB 3.0, then the manufacturer doesn't need to include a 3rd party chip (that is, unless they're trying to build a board that supports more USB 3.0 devices than the chipset itself can handle). if the motherboard's chipset doesn't support USB 3.0, a 3rd party chip must be included in the manufacturing process in order to provide USB 3.0 support...hope that makes a little more sense.

 

[officerping]

Yes, that definitely makes sense. If I understood you correctly, the chipset (X79) does not support USB 3.0, so the motherboard's manufacturer must provide a separate USB 3.0 controller.

Thanks!

 

[officerping]

Based on your recommendations, I'll be going with Sandy Bridge-E. I'll mull over whether to spend $200 extra on the 3930K; extra cores are nice. Thank you all for the good discussion!

 

[bunnyfubbles]

Can you clarify why USB3.0 support can come from either the motherboard or the CPU? I'm a bit confused here.

Intel's 7 series IvyBridge chipsets (such as the Z77 used in the mothebroard that you are looking at for the 3770K build) has the USB3.0 controller included in it. For X79 Intel only included a USB2.0 controller. To get USB3.0 support for any chipset X79 and older, a 3rd party USB3.0 controller chip has to be added on to the motherboard.

I meant that smaller transistors was "cooler" in a nerdy way.

Well it can still be something to consider. My 3930K @ 4.7GHz can put out a good deal of heat, granted if you're going to be running two GTX480s, the heat the CPU puts out will likely be pretty trivial.

I'll look into the BIOS. What number is changing from 100 to 125 precisely? I'm completely new when it comes to overclocking, so I don't know the distinction between the FSB and multiplier.

basically all Sandy and Ivy chips operate with a 100MHz bus speed commonly referred to as the base clock (or BCLK). Quite simply, the CPUs achieve their respective clock rates by multiplying the BCLK.

The 3770K has a 35x multiplier and thus operates at 3.5GHz, however the K series CPUs have an unlocked multiplier and thus can be changed to whatever value you desire (up to 63 or something for Ivy) and thus overclocking to 4.5GHz is as simple as changing the multiplier to 45, and then making sure the chip is receiving enough volts to be stable (as well as keeping it cool)

The 3820 has a 36x multiplier and thus operates at 3600MHz, or 3.6GHz. However the advantage of SB-E is that you can change the BCLK from 100 to 125, 166, or even up to 250 without compromising stability.

For the 3820, while we do not have the luxury of an unlocked multiplier (although, IIRC, it can go up to 43x) we can exploit the ability to change the BCLK in order to match the 3770K's ability to hit 4.5GHz. In the case of trying to hit 4.5GHz on a 3820, changing the BCLK from 100 to 125 and remaining at the stock 36x multiplier would do just that.

The main advantage of the 3930K is two more cores. I'm still considering it, but it's kind of a minor option.

Oh that's for certain. However it does have that slight advantage over the 3820 in terms of overclocking "ease", not that the 3820 isn't just as capable of hitting the speeds you would want it to, it would just take a little bit more tweaking

 

[officerping]

Thanks for the information. I'm probably going with the i7-3820, due to the lower cost and some more comparisons (http://www.tomshardware.com/reviews/core-i7-3930k-3820-test-benchmark,3090-9.html) which show that it gives improved performance for single threaded processes. When Ivy Bridge-E comes out, I'll consider swapping the CPU for a faster one.

Based on your explanation, I can overclock the i7-3820 by increasing the base clock to 125 MHz. That sounds like a good option. Is there a recommended voltage that I need to set in the BIOS as well, or does the motherboard set the voltage automatically?

I'm considering the ASUS P9X79 PRO motherboard: http://www.newegg.com/Product/Produc...82E16813131800

Looks like it can support up to four GPUs and it has a USB 3.0 controller.

My last question is regarding the CPU cooler. I'd like to try the Noctua NH-D14 (http://www.newegg.com/Product/Produc...82E16835608018), but it looks really huge and I'm worried it won't fit. Does anyone have experience with this?