Sunday, October 2nd 2011

Sandy Bridge-E VT-d Broken In C1 Stepping, Fixed In C2 Stepping, Shortly After Launch

PC enthusiast customers and companies running corporate datacentres looking to buy into the new Sandy Bridge-E platform may want to wait a little while before handing over their hard-earned money to Intel. The initial batch of C1 revision Sandy Bridge-E processors have a bug - "errata" in Intel terminology - in them with VT-d, which means that hardware accelerated virtualization doesn't work properly with them (software only mode is unaffected). The feature when working properly, allows all hardware acceleration to work on the hosted operating system (virtual machine). This would allow things such as hard drive controllers to work, plus applications such as high-powered 3D games, typically First Person Shooters, to run at nearly full speed and the full Windows Aero desktop to be displayed on the hosted OS, as the hardware features of the graphics card can be used. Therefore, working VT-d is a critical feature for these kinds of applications.
Production of the C1 stepping should have already started, or is about to start. However, the C2 stepping isn't expected until next year, as the qualification process isn't expected to be complete until the end of this year.

Intel will only certify the Waimea Bay platform for PCI Express 2.0 at launch, since there aren't enough third party cards to test with. Some PCI Express 3.0 devices are still likely to work, but Intel doesn't guarantee compatibility. This doesn't bode well for the current 6-series motherboard with gen 3 switches actually working properly once cards and especially, Ivy Bridge processors arrive. Waiting for full qualification before purchasing is therefore advised, or an expensive motherboard replacement may be required in the not too distant future.

There is some good news however. For those wanting to continue using Windows XP, the Waimea Bay platform will be compatible with both 32-bit and 64-bit versions of the operating system. However, Intel won't be providing Rapid Storage drivers for 32-bit XP, which means that the basic Windows drivers will be handling drive access, which may not be optimal. Unsurprisingly, the upcoming Waimea Bay platform will also be supporting the upcoming Windows 8, when released.

It's not so good on the chipset front, either. Intel has increased the price of the X79 chipset by 20% compared to the X58 chipset, putting the X79 chipset somewhere in the region of $70. This is the list price, so the discounted or "street" price should be a lot lower. However, we are looking at a chipset that offers no new features over X58 and it's the same size as the 6-series chipsets - it should be cheaper to manufacture than the X58 chipset which only consists of the I/O Hub and the ICH10R. We wish AMD well with their new processors and chipsets, as competition can only be a good thing here and is clearly needed.

It's one thing for "errata" to be discovered some time after a product has been released and then to manufacture a revised processor, but it doesn't seem right for Intel to release processors with a known major feature fault like this, especially as most buyers are unlikely to know about it and Intel is even less likely to shout about it. Therefore, buyers would be wise to wait for the bug-fixed C2 version before upgrading, unless they are absolutely sure they won't need this virtualization feature. After all, are Intel going to offer a free replacement to the fixed version for customers of the initial C1 versions? Only this gesture can make releasing such an obviously flawed product right. Intel have offered such a free replacement recently with the faulty SATA controller, so there's hope yet they'll do the right thing. And just as importantly, it's worth keeping a close watch on what significant errata C2 might harbour, before upgrading.
Source: vr-zone.com
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49 Comments on Sandy Bridge-E VT-d Broken In C1 Stepping, Fixed In C2 Stepping, Shortly After Launch

#26
zsolt_93
What about these?
2820QM
2600
Some i7s have vt-d and even mobile models do. So no Xeons here. Playing games on a virtual machine depends from vt-d so there was nothing wrong in the OP.
Posted on Reply
#27
Sihastru
Mobile platforms yes, because those platforms are multi-purpose. I did say desktop platforms, also I don't think we have Sandy Bridge E on X79 motherboards laptops. Not yet anyway.

The desktop processors that do support VT-d, require a special chipset, braded as "Q", Q67 for example, for the 2600, with compatible BIOS, and that is a workstation chipset meant for enterprise. Even there you can't be sure you'll have full VT-d support, they will only give you AMT support (that requires some VT-d features).

Do not confuse VT-d with VT-x.

Also for those thinking that buying a Bulldozer is the answer, AMD-Vi is not supported on the desktop variants, you'll need to buy an "Opteron" part. Also, don't confuse AMD-V with AMD-Vi (for IOMMU). Again, you'll need a server motherboard, your desktop motherboard won't support AMD-Vi.
Posted on Reply
#28
shb-
I see no real problem here, 2600K does not have VT-d at all, and nobody seems to have problem with that. On most mobos/bioses VT-d is disabled by default, so god only knows how many nahalems/other VT-d capable CPUs are actually running with it disabled. I think only few of those hardcore gamers/encoders/OCers who are looking towards X79, truly care about virtualization.

Its good to know of course. And it’s still nice to have it, although u don’t actually use it (for e-dicks sake).

And afaik virtual box does not support VT-d, yet:
www.virtualbox.org/ticket/5252
so only those who have VMWare licenses can utilize it.
Posted on Reply
#29
Disparia
^ The 2600 and 2600 do have it, which is why you might not many people taking issue with it.
Posted on Reply
#30
[H]@RD5TUFF
FordGT90ConceptI think there's a fair bit of exaggeration going on. Intel would not release a server-class processor without VT-d functionality (equivilent of shooting one self in the foot). It has a bug, but I highly doubt it is completely dysfunctional.
Kinda how I see it.:toast:
Posted on Reply
#32
zsolt_93
K models are missing Vt-d. Apart from that tyhere are even i5 s like the 2400 with it.
Posted on Reply
#33
FordGT90Concept
"I go fast!1!11!1!"
Yeah, I just noticed that. S models have it too. Not K.
Posted on Reply
#34
Jegergrim
qubitSome PCI Express 3.0 devices are still likely to work, but Intel doesn’t guarantee compatibility. This doesn’t bode well for the current 6-series motherboard with gen 3 switches actually working properly once cards and especially, Ivy Bridge processors arrive. Waiting for full qualification before purchasing is therefore advised, or an expensive motherboard replacement may be required in the not too distant future.
Why doesn't this bode well with the lga 1155 6 series boards with gen 3 switches?
Posted on Reply
#35
Disparia
FordGT90ConceptOnly the non-K models have VT-d. How Ironic.

List of processors with VT-d.
Yup. Gotta check per chip these days. Intel throws in an 'asterisk' or two here and there, breaking series commonality. Ex: All 34xx Xeons have HyperThreading * Except the X3430.
Posted on Reply
#37
Inceptor
eidairaman1So why does the high end not have everything?
The SB 'K' parts are specifically marketed to home desktop users interested in overclocking. Everything else with VT-d can be sold to corporate and government customers who might have the need for such a thing.

The C1 stepping of SB-E not having VT-d will only affect users who need hardware virtualization...
Although I'm sure it will also reduce the sales of SB-E to home users who have no use for VT-d, just because of the appearance of a problem (for their usage of the chip).
Posted on Reply
#38
FordGT90Concept
"I go fast!1!11!1!"
Here's the comparison of the three 2600 models. There's actually lots of pretty significant differences among them:
ark.intel.com/compare/52215,52214,52213

Most notable:
-S has a lower base clock (2.8 GHz vs 3.4 GHz) and as a consequences, a 65w TDP instead of 95w.
-2600 has Embedded Options Available (longer support lifecycle)
-K has HD 3000 while S and 2600 have HD 2000
-K does not have vPro, VT-d, nor Trusted Execution Technology support.
JizzlerYup. Gotta check per chip these days. Intel throws in an 'asterisk' or two here and there, breaking series commonality. Ex: All 34xx Xeons have HyperThreading * Except the X3430.
Curse them for not K.I.S.S.ing. :banghead:
Posted on Reply
#39
de.das.dude
Pro Indian Modder
looks like we need another new news editor.
Posted on Reply
#40
eidairaman1
The Exiled Airman
InceptorThe SB 'K' parts are specifically marketed to home desktop users interested in overclocking. Everything else with VT-d can be sold to corporate and government customers who might have the need for such a thing.

The C1 stepping of SB-E not having VT-d will only affect users who need hardware virtualization...
Although I'm sure it will also reduce the sales of SB-E to home users who have no use for VT-d, just because of the appearance of a problem (for their usage of the chip).
be honest here if its a high end unit i want all the functions of it on there. TBH intel is confusing with all this crap now
Posted on Reply
#41
FordGT90Concept
"I go fast!1!11!1!"
Overclock & decent integrated graphics: 2600K
Save power: 2600S
Otherwise: 2600
Posted on Reply
#42
[H]@RD5TUFF
Intels naming scheeme isn't that hard to understand .. .
Posted on Reply
#43
qubit
Overclocked quantum bit
JegergrimWhy doesn't this bode well with the lga 1155 6 series boards with gen 3 switches?
Because when PCI-E 3.0 becomes mainstream, everything in the chain must work together to deliver it, so if some part is out of spec the whole thing fails (and falling back to spec 2.0 for partial functionality would be a failure). If Intel isn't able to qualify compatibility, then you can just see mobos released without this certification being decidedly flakey and everyone shirking responsibility when people try to claim under warranty. In short, it'll be ugly.
Posted on Reply
#44
parelem
eidairaman1be honest here if its a high end unit i want all the functions of it on there. TBH intel is confusing with all this crap now
the whole 1155 platform is NOT high end, it's mid range.
Posted on Reply
#45
eidairaman1
The Exiled Airman
regardless they released a CPU that is high end for it, aka Core i7, which is on 1366 aswell, core i7 i recalled was the high end cpus.
Posted on Reply
#46
Inceptor
eidairaman1regardless they released a CPU that is high end for it, aka Core i7, which is on 1366 aswell, core i7 i recalled was the high end cpus.
The operative word being 'was'.
Core i7 is now only 'high end' when associated with Sandy Bridge Extreme.
Core i7 2xxx are now only 'mid-range performance cpus'
Welcome to the present.
Posted on Reply
#47
FordGT90Concept
"I go fast!1!11!1!"
Core i7 = performance
Core i5 = mainstream
Core i3/Pentium/Celeron = budget

LGA 1366/2011 = enthusiast/workstation/entry-level server (high premium on motherboards largely due to the chipset)
LGA/BGA 1156/1155 = desktop/laptop
Posted on Reply
#48
Thefumigator
SihastruMobile platforms yes, because those platforms are multi-purpose. I did say desktop platforms, also I don't think we have Sandy Bridge E on X79 motherboards laptops. Not yet anyway.

The desktop processors that do support VT-d, require a special chipset, braded as "Q", Q67 for example, for the 2600, with compatible BIOS, and that is a workstation chipset meant for enterprise. Even there you can't be sure you'll have full VT-d support, they will only give you AMT support (that requires some VT-d features).

Do not confuse VT-d with VT-x.

Also for those thinking that buying a Bulldozer is the answer, AMD-Vi is not supported on the desktop variants, you'll need to buy an "Opteron" part. Also, don't confuse AMD-V with AMD-Vi (for IOMMU). Again, you'll need a server motherboard, your desktop motherboard won't support AMD-Vi.
Opteron are cheap, unlike intel server platforms, you could buy a dual socket C32 motherboard with [whatever opteron available for that socket], for less than 1000$, just take a look at newegg.

On the other side, AMD-Vi seems interesting (hey, having direct access to each hardware part sounds really cool) But in my case I only know that each AMD processors in existance supports AMD-V and its the only thing I need for running my Virtual Box at decent speed. And the difference is noticeable with AMD-V turned off.

Unlike intel and its VT, all amd processors support AMD-V. Except perhaps, zacate and llano. No wait, llano supports it. Zacate too!
Posted on Reply
#49
TheGuruStud
Comparing this to barcelona is retarded. You couldn't reproduce that TLB if you tried. This feature just doesn't work. Two entirely different things.

But don't let that stop anyone from spewing crap (about either side). :banghead:
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