damric :
I'll give some layman's terms definitions. I think you are getting confused on the IMC, NB, and HT Link, especially since those are a lot different on older intel platforms, which is why I mentioned your curriculum is out of date (by quite a few years).
Base Clock: For the AM3+ platform, you have what's called the base clock. It's basicly similar to the old FSB. It's default clock for this platform is 200MHz, and it get's multiplied against everything else to control various frequencies. Other than that, it doesn't actually do anything.
CPU Frequency: This is controlled by a multiplier. Base clock x CPU multiplier = CPU frequency. This is the main factor for performance.
CPU-NB: This is the on die memory controller. For AM3+, it's on the CPU die. It controls L3 cache speed, and also relays data from RAM to the CPU. This also has a multiplier. Base clock x CPU-NB multi = CPU NB Frequency. Overclocking this can improve latency. For Bulldozer/Piledriver chips, this will be a bottleneck if running less than 2x RAM frequency. Example: for DDR3-2000, it would need to run at least 2000MHz since RAM is running 1000MHz double data rate. In older platforms this wasn't built into the CPU.
RAM Speed: Self explanatory. DDR is double data rate, so for example a DDR3-1600 module runs at 800MHz or 1600MT/s, often mistaken for running ar 1600MHz. This is controlled by the RAM multiplier and your base clock. So again example: base clock 200 x4 would give you 800MHz or 1600MT/s. I'm not going to get into bandwidth and timings, as that's a whole discussion by itself.
Hyper Transport Link: This is communication between the CPU and the chipset northbridge. On newer platforms the chipset northbridge is on die so this will be N/A like on the FM2/+ platform. But on AM3+ you still have a chipset northbridge. I've seen this usually default at 2600MHz (5200MT/s) for AM3+ CPUs. You can raise or lower this as needed, but this has less of an impact on performance than changing anything else.
Now if you are wondering what the biggest bottleneck on this platform is...
In my opinion it's the L1, L2, and L3 cache speed/latency in the CPU itself. It's horrible.
If you need older info related to your studies, I would suggest checking out some of the older overclocking guides on overclock.net and techpowerup.com. The definitions of components would be more relative to what you are supposed to be learning I think.
Thanks Damric, I appreciate you taking the time to clarify those terms. From the exam book I was able to figure out that some of the functions of the Northbridge were moved to the cpu on new systems, like the memory controller. I also read that Intel includes the controller for the gpu on the cpu as well, removing the need for the seperate NB. The exam book is pretty general though; it'd be nice if there were more examples of newer systems in there. I guess it just gives the broad picture for the exam. So I believe I do know some of the basics on how the newer systems are connected, but obviously not much beyond that. I hope you don't mind, but I have some questions regarding the terms you've listed. I've read the various definitions of some of these terms on wiki and other sites, but I still don't feel like I really know everything about them.
Baseclock: Is this determined by the motherboard, the cpu, or am I totally off base?
CPU Frequency: Looking at the specs for my cpu, it has the following 2 boost states:
1) 4000 MHz, 1.425V
2) 3700 MHz, 1.4125V
On CPU-Z it shows the multiplier between 7-20. I can see that depending on the load, the multiplier adjusts. So doing the math, 200Mhz x 20= 4000Mhz, the cpu's highest power state. The 18.5 multiplier is used for the 3700Mhz power state and so on with the lower power states. My question is, what if the base clock of my system is something like 100Mhz? Does the system compensate and use a larger multiplier in order for the cpu to hit it's rated power state frequencies? I also find it strange that a 3.5 Ghz CPU doesn't have a power state that sits at 3.5 Ghz. The closest is 3.7 Ghz.
CPU-NB: This one confuses me a bit. So there is a northbridge on die(in the cpu) and a chipset NB on the motherboard? Of course I'm just referring to some of the newer AMD boards. So the CPU-NB only controls memory while the Chipset NB controls PCIe adapters, USB3 and gpu's?
RAM: On my motherboard specs it says it supports 1333+ (O.C.)/1066 MHz memory modules. I purchased 2 sticks of DDR3 1600 that are each running at 800Mhz, I verified this on CPU-Z. I was one of those who thought DDR3 1600 (MT/s) meant 1600 Mhz. So my mother board specs are referring to supporting DDR3 2666 (O.C)/DDR3 2133 right? The spec sheets also mention that everything above DDR3 1600 is downgraded to DDR3 1600. So I guess it would not make sense to spend more on DDR3 2133 when its going to downgrade it anyway.
Hyper Transport Link: This is obviously what concerned me when I saw my CPU NB was rated at 5200 MT/s and the HT link was at 4400 MT/s. In my pc's bios, the cpu northbridge freq is at 2200Mhz as well as the HT Link frequency. So, to me, it looks like the CPU NB is being limited by the HT Link frequency. I'm not understanding that relationship there. Also on
CPU World.com it says the CPU's bus speed is 2600 Mhz HT Link. Is that the CPU NB frequency? This is where I'm really lost.
Regarding the info I'm studying, I would like to learn the most up to date technology as well, it just seems these books like to give the history of how we got to this point. I guess its also done in case we come across the need to repair an outdated system. I would like to dig deeper into the Cache and how that can bottleneck a system, but I think I've already asked too many questions, lol. Thanks again for taking the time to pass on some knowledge.
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