Another big reason Xeon is in trouble next year?

willfr

Member
Apr 27, 2016
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Everyone is so focused on performance per watt and performance per dollar but, if I'm not mistaken, next year AMD will have hardware fixes for Spectre* and that seems like a big factor in the decision making. There's always new variants being found and that has to be a huge pain for companies, they won't have to worry about that if they go with AMD. Tough times ahead for Intel...





*I'm not an expert at all and don't understand if Meltdown also applies to AMD. AMD claims it doesn't?
 

Dayman1225

Golden Member
Aug 14, 2017
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Intel's Cascade Lake based Xeons that are launching this year have in hardware mitigation's.
 

Markfw

Moderator Emeritus, Elite Member
May 16, 2002
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Everyone is so focused on performance per watt and performance per dollar but, if I'm not mistaken, next year AMD will have hardware fixes for Spectre* and that seems like a big factor in the decision making. There's always new variants being found and that has to be a huge pain for companies, they won't have to worry about that if they go with AMD. Tough times ahead for Intel...





*I'm not an expert at all and don't understand if Meltdown also applies to AMD. AMD claims it doesn't?
Meltdown ONLY applies to Intel, but the fix for it, is the big performance hit on servers. Spectre has fixes from both AMD/Intel in software, and the performance hits are negligible.
 

IEC

Elite Member
Super Moderator
Jun 10, 2004
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Meltdown ONLY applies to Intel, but the fix for it, is the big performance hit on servers. Spectre has fixes from both AMD/Intel in software, and the performance hits are negligible.

Spectre fixes actually have a pretty significant impact on server usage on Xeon platforms. Worse impact on v3 and v4 Xeons vs Skylake/Scalable.

It's the IBRS (Indirect Branch Restricted Speculation) mitigation for Spectre Variant 2 (Branch Target Injection) which has the worst impact (so far) on CPU util and response time metrics. This is causing a lot of orgs to disable that mitigation in Windows registry on guest machines until they can get additional hardware to offset the increased utilization, though it doesn't solve the response time issues caused by the mitigation...
 

Markfw

Moderator Emeritus, Elite Member
May 16, 2002
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Spectre fixes actually have a pretty significant impact on server usage on Xeon platforms. Worse impact on v3 and v4 Xeons vs Skylake/Scalable.

It's the IBRS (Indirect Branch Restricted Speculation) mitigation for Spectre Variant 2 (Branch Target Injection) which has the worst impact (so far) on CPU util and response time metrics. This is causing a lot of orgs to disable that mitigation in Windows registry on guest machines until they can get additional hardware to offset the increased utilization, though it doesn't solve the response time issues caused by the mitigation...
So, the spectre fixes fixes for AMD are minimal impact though ?
 
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