Search the Community

It seems that quite a bit of info has come out about the zen architecture thanks to David Kanter, who was the same guy who figured out that nvidia's Maxwell and Pascal GPU architectures are utilizing tile based rasterization. You can check out his full deep dive here. Now I won't pretend to even understand half of it, but some of those of you out there with EE, CE, CS, or any other major that required extensive knowledge about CPU architecture may find it quite interesting. As well, if you're interested, David Kanter also did an interview with PCPer about the zen architecture which you can check out here: I think that all this info arose from ISSCC. I've found it quite interesting even if I didn't understand all of it. It seems though that zen won't be very suitable for HPC; perhaps they did this to save die space in order to maximize profits of consumer and server CPUs. As well, it seems zen ipc would be between Ivy bridge and haswell. I'm honestly not surprised, there have only been a limited amount of official benchmarks from AMD and since they were the ones showing them off I wouldn't be surprised if they were cherry picked. However, even if it's only ivy bridge IPC, zen still could very well shake up the whole CPU market.

Hello! I'm a high school student but I'm looking into doing dual enrollment and college courses eventually. I don't know what courses would help me get the type of job I'm trying to get. What I want to do is make CPUs, but I want to do the actual computer part. Like the coding part, not the machinery part. What job is that? And what courses could I take to help me get a better understanding of that? Thanks!

I have two computers. Both computers have the same 560ti graphics card, both run an SSD boot drive, both have 8gb memory and both are in the same case with similar thermals. The difference is the CPU (and motherboard but that shouldn't affect performance) One system runs an overclocked Sandybridge 2600K (hyperthreading off) while the other runs a Haswell 4770 (hyperthreading on). Two generations appart from each other, while both being 3.4gHz i7 processors However the computer with the Sandybridge processor is severely underpowered it appears compared to the Haswell computer. For example, in Space Engineers both can run a single player world just fine (sandybridge running at 90-100% CPU usage while haswell running at 60-80%) but when multiplayer is introduced, specifically other playes moving around in ships, the workload increases (Sandybridge sitting at 100% the whole time with about 2 FPS while Haswell sits at 90-100%) Similar performance issues can be noticed in late game Game Dev Tycoon (a large studio with all sorts of events happening). Frame rate drops to about 2 FPS on Sandybridge (don't have it on Haswell) and because in-game clicking is tied to frame rate makes the game close to unplayable. Re-loading the game helps in the short term. Not sure why it does that. Late game Prison Architect (with 500 prisoners and appropriate staff to match) on Sandybridge runs at 4FPS. Similar large game on Haswell runs at about 80% usage. Simcity 2013 (any city size over 40K people) will run at 4FPS on Sandybridge while smooth on Haswell up to about 120K All of those games are multithreaded workloads. The Haswell system also runs Windows 8 vs Win. 7 on Sandybridge but i don't think that should explain the performance gap. My question is this: Does CPU architecture explain this change or is another variable bottlenecking my Sandybridge system? in some of these games (SC 2013, Space engineers) GPU also sits at 100% usage, however it is the same for both systems with the same model of graphics card (560ti Asus twin frozer cooler) also, I imagine upgrading to haswell or Devil's Canyon would match performance but would buying a xeon 6 core processor or waiting til Q3 for Intel's new 6 core thing improve more so? is it worth the extra money in this instance to upgrade beyond gaming hardware into enthusiast/extreme? Thank you. =) Any assistance

Hi Everyone, I uploaded a video that discusses the possibility of AMD releasing a brand new CPU and why we would want this to happen. I though a tech forum would be an ideal place to share it so tell me what you think and whether you agree with what I said. https://www.youtube.com/watch?v=EVBY7zw-o0M

For my first post here on LTT Forums, I thought I might write something a bit in depth. After AMD's Ryzen launch, some light was finally shed on the underdog. With this, sales of the older FX series had increased. Because of the confusing architecture of the FX series, many people have made false claims like the following "the FX-8xxx and FX-9xxx series only have four cores" and "AMD's Bulldozer/Piledriver cores are weaker than Intel's cores". I will explain how people could believe these claims, but also how they are incorrect. I will first explain the naming scheme of the FX series. First, we have the FX-4xxx lineup. The FX-4350's "4" stands for the amount of cores. The "3" stands for the generation. You may be wondering "how are there three generations when there was only Zambezi and Vishera?" Well, Zambezi CPUs had revisions of certain CPUs half way through release. There was an FX-6100, which, from the number "1" shows it is the first generation. Then, there was an FX-6200 released, being the second generation. So, now that I have explained generations, we can get back to the naming scheme. The FX-4350's "5" stands for a revision or a step above another product like the FX-4300. Usually, a higher model number indicates more performance. So, now that you understand the naming of the SKUs of the FX series, we can dive into the actual Bulldozer/Piledriver architecture. I will start by explaining what the Bulldozer and Piledriver names mean. Bulldozer was the name of the architecture Zambezi CPUs were based on, so, the first and second generation CPUs. Piledriver was a slightly modified version of Bulldozer, used on current third generation FX series CPUs. Now we'll get to the technical aspects of the architectures. Bulldozer/Piledriver used something called CMT, or Clustered Multithreading, which is the implementation of cores in "modules". One AMD module consists of two cores, so, an FX-8350 would have four modules, making a total of eight cores. Using CMT allows more cores to be packed into the same or smaller area as a "traditional" core by forcing the cores to share resources, such as a floating point unit, or FPU. AMD also chose to use CMT to reduce power consumption, as there were fewer dedicated parts that used high amounts of electricity. So, now I will explain the false claims listed above. The FX series' CPUs have 100% real, physical, cores. Even though Windows Task Manager may disagree and display only four physical cores and eight logical cores, there are really eight physical cores. When both cores in a module are running Integer operations, the module acts as a dual core CPU. When both cores are running 128-bit FP operations, the module will once again act as a dual core. The module can also perform a mix of integer and 128-bit operations, and still perform similarly to a dual core CPU. There is only one case that the module will act as a single core CPU. Both cores in the module share two FPUs, each 128-bits, but for situations where a program calls for 256-bit code, AMD developed a solution called Flex FP. Flex FP allows the two 128-bit FPUs to combine into one 256-bit FPU. When this happens, one core can no longer run floating point code because both FPUs are being used by the other core for 256-bit operations. The core that cannot use the FPU can still run integer code at the same time the other core is running the FPU and integer code. At the time of release, very few programs used 256-bit code, eliminationg the need to disable a core's floating point capabilities. The second point I would like to touch base on is, AMD CPUs do not use Hyperthreading. AMD's Ryzen CPUs use SMT, or Simultaneous Multithreading, which is very similar, but it is not Hyperthreading. SMT is the alternative to CMT, with an SMT core being roughly the same size as one CMT module, possibly packing more ALUs or AGUs. SMT has one core, but can split the amount of ALUs across two threads, therefore creating two smaller "cores". Another misconception of the Bulldozer/Piledriver architecture is that the cores are "weaker" than Intel's. This is simply not true. On paper, Bulldozer should have crushed Intel's offerings. AMD supported many of the same instructions as Sandy Bridge. Bulldozer, in fact, actually supported more instructions (XOP, FMA4, F16C) than Sandy Bridge, but were not implemented by developers. The real reason why AMD's Bulldozer architecture underperformed was because of branch misprediction due to an underpowered branch prediction module, poor instructions per clock (IPC), and long pipelines. Bulldozer's IPC was pretty bad. The 2010 Phenom 1090T could outperform some of the FX CPUs clock-for-clock. The FX CPUs could have crushed the Phenom CPUs with their high clock speeds, but with long pipelines, the CPUs were more susceptible to branch misprediction, causing the CPU to completely restart the instruction it was just working on. By all means, I am not an AMD fanboy, nor am I an Intel fanboy. I have covered some of the pros and cons of the FX CPUs. I am a proud owner of an FX-4300, and believe me, that thing has held up greatly. It runs well for my motherboard having a broken VRM as well. I might not be able to play the newest games at a solid 60 FPS, but I still get by on Battlefield 1 and other somewhat demanding games. I am very surprised at how long the FX CPUs have lasted. Even with much lower Hypertransport speeds than Intel's solution, the FX CPUs can still compete. The FX CPUs could have been amazing if developers had used them to their full potential. I believe the FX CPUs were simply underutilized, and with DirectX 12, we're starting to see some major performance improvements in gaming. I am also very surprised at how slowly the FX CPUs have aged. I think to myself, "how can a six year old architecture still compete with the newest technology?" We all know the answer to that question though. Intel simply milks the consumer by releasing a modified architecture every year with minimal performance increases. What I would really like to see is a new AM3+ motherboard lineup with PCIe 3.0 and newer peripherals. If you read this whole post, I appreciate it. I apologize for any confusing parts of this post or any parts that don't make sense as I haven't looked over it for mistakes.