Message boards : Number crunching : performance loss through patches against Meltdown and Spectre
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Erich56 Send message Joined: 1 Jan 15 Posts: 1091 Credit: 6,619,656,926 RAC: 3,907,698 Level  Scientific publications      | |
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what I am very curious about is how much the CPU performance loss through the patches against Meltdown and Spectre, which for Windows will be published shortly, and for Linux allegedly have been distributed already, will affect GPUGRID crunching. | |
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Keith Myers  Send message Joined: 13 Dec 17 Posts: 1288 Credit: 5,119,681,959 RAC: 9,393,321 Level Scientific publications  | |
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So far, the tests I have seen show almost no performance loss in typical computer workloads. Some performance loss, about 3% in synthetic benchmarks for certain tests. Most of the performance loss will be in the datacenters. | |
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 Retvari Zoltan Send message Joined: 20 Jan 09 Posts: 2343 Credit: 16,201,255,749 RAC: 851 Level  Scientific publications | |
patches against Meltdown and SpectreFYI: there are at least one kind of Spectre attacks, which in theory (therefore in practice) can't be fixed by software patches, as these attacks exploit the effects on the cache of the "out of order execution" scheme of the CPU (which is hardwired to the chip). It means that these CPUs are basically doomed. There are mayor breakdowns ahead of us in every area of our lives. | |
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Erich56 Send message Joined: 1 Jan 15 Posts: 1091 Credit: 6,619,656,926 RAC: 3,907,698 Level Scientific publications | |
...It means that these CPUs are basically doomed. There are mayor breakdowns ahead of us in every area of our lives. nice to read :-) | |
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Retvari Zoltan Send message Joined: 20 Jan 09 Posts: 2343 Credit: 16,201,255,749 RAC: 851 Level Scientific publications | |
From the smiley I think that the severity of this bug is simply too unthinkable, but one app reading the other app's memory without any software or hardware could detect it is simply the end of any kind of cyber security. No passwords, financial records, PIN codes, nothing is safe from now on. That is basically the end of the world as we know it....It means that these CPUs are basically doomed. There are mayor breakdowns ahead of us in every area of our lives.nice to read :-) | |
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Jim1348 Send message Joined: 28 Jul 12 Posts: 819 Credit: 1,591,285,971 RAC: 0 Level  Scientific publications | |
That is basically the end of the world as we know it. Does this mean that "out of order execution" can't be used at all, or just needs to be implemented differently? It sounds like a good opportunity for AMD and Intel to sell more chips. | |
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Retvari Zoltan Send message Joined: 20 Jan 09 Posts: 2343 Credit: 16,201,255,749 RAC: 851 Level Scientific publications | |
Does this mean that "out of order execution" can't be used at all, or just needs to be implemented differently?There are CPUs without "out of order execution" which are safe - those are the slowest, cheapest ones (some older Atom CPUs for example), so the first part is true. The present implementation of the "out of order execution" with a little addition (=new CPUs) would be safe from the present implementation of Spectre attacks, but the present architecture thought to be safe for more than 20 years. No one can tell how long it takes to "hack" the modified architecture as well. It sounds like a good opportunity for AMD and Intel to sell more chips.Provided that there will be anybody to buy it. | |
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Jim1348 Send message Joined: 28 Jul 12 Posts: 819 Credit: 1,591,285,971 RAC: 0 Level Scientific publications | |
Provided that there will be anybody to buy it. It is a strange way for civilization to end: The Out of Order Apocalypse. | |
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Richard Haselgrove Send message Joined: 11 Jul 09 Posts: 1576 Credit: 5,789,286,851 RAC: 9,192,345 Level Scientific publications | |
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Reposting from SETI: Spectre vulnerability affects Nvidia cards It isn't just CPUs, apparently. | |
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Erich56 Send message Joined: 1 Jan 15 Posts: 1091 Credit: 6,619,656,926 RAC: 3,907,698 Level Scientific publications | |
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I am just reading something rather worrrying in the LHC forums, with regards to the Meltdown/Spectre patches: | |
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3de64piB5uZAS6SUNt1GFDU9d...  Send message Joined: 20 Apr 15 Posts: 285 Credit: 1,102,216,607 RAC: 0 Level  Scientific publications | |
It is a strange way for civilization to end: The Out of Order Apocalypse. Well, it is alarming indeed. On the other hand, we should not overrate Spectre. If one (malignant) application can access some memory content of another by reading the pre-fetch, it basically means that you must have that malware on your computer already. And if so, you could already do a lot of other bad (but already existing) things, which are cheaper to implement, installing keyloggers for example. So Spectre is not necessarily the end of days ... but it's the large attack surface which makes it grievous and will cause us some headache for the next couple of months. Well, I guess both NSA and KGB know a few gaps other than that, which are not known yet but also inherent to the architecture. And if a powerful organisation really wants to know your online banking password, they will contrive ways and means, be sure about that! All that protects us ordinary people is our unimportance and relatively low bank balance. It is a cold comfort, I know. ____________ I would love to see HCF1 protein folding and interaction simulations to help my little boy... someday. | |
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Jim1348 Send message Joined: 28 Jul 12 Posts: 819 Credit: 1,591,285,971 RAC: 0 Level Scientific publications | |
If one (malignant) application can access some memory content of another by reading the pre-fetch, it basically means that you must have that malware on your computer already. And if so, you could already do a lot of other bad (but already existing) things, which are cheaper to implement, installing keyloggers for example. Sure. The AV software should offer us ordinary users the usual degree of protection. Whether it is so easy to protect servers I don't know, but they will think of something. | |
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Erich56 Send message Joined: 1 Jan 15 Posts: 1091 Credit: 6,619,656,926 RAC: 3,907,698 Level Scientific publications | |
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Some further information: | |
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JStateson Send message Joined: 31 Oct 08 Posts: 186 Credit: 3,331,546,800 RAC: 0 Level  Scientific publications | |
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The only problem I have had related to those possible threats is that the ubuntu "fix" for it in kernel 4.13.0.32 broke the nVidia CUDA OpenCL package. I had to revert back to my original 4.13.0.19.generic to get my CUDA cards crunching again. I found a complaint at the nVidia github where developers complained that too many changes went into the 32 kernel which caused their code to fail. | |
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Message boards : Number crunching : performance loss through patches against Meltdown and Spectre
