RAM speed as a function of the processor
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Hello.
I have a question about speeds that I couldn't quite find the answer to on Google.
I read something about the processor's FSB limiting the speed of the RAM. Specifically this:"A microprocessor that works with a clock speed of 333 Mhz (FSB at 333*2=667), the ideal thing will be to put a memory of 667 Mhz"
But does that 333MHz refer to the processor's clock speed?
A processor with these characteristics:
Bus frequency 5000 MT/s
Clock frequency 3500 MHzIs any of this data limiting the speed of the RAM? What would that speed be?
I would greatly appreciate it if someone could explain this to me.
Thanks in advance.
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The FSB does not limit the speed of the memory, if anything it would be the other way around. Although the controller is natively 667@stock, you can put them at 800 if they can handle it. Another thing is whether or not it is noticeable, but that is another story.
As for limitations, to handle those 333MHz base clock you will need some memory that can handle 667. It's not that you have much of a problem here for stock frequencies, any 533 can handle 667 even if you give it some voltage. With some old memory and overclocking you could have problems. With the era of core2 everyone had memory at 667MHz that, at worst, between extra voltage and relaxed latencies does not limit OC.
It's not an issue to get worked up about, if anything, related to this, there would be debate about how much it is worth buying fast memory on current platforms. The truth is that the impact is very low but well, we are getting faster memory cheaper and platforms that get a little more out of those clocks. If with the first Sandy Bridge going beyond 1600MHz was not profitable, now 1866 is not a bad idea either.
What kind of micros are you talking about? An i7?
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The processor is an i7-3770K has an FSB of 100MHz.
From these 100MHz, what would be the calculations to know what speed of RAM is perfect?
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The FSB as such no longer exists in current processors, look for what DMI is and you will understand why you are wrong. Basically the memory controller is integrated into the CPU and the connection is therefore direct.
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The i7-3770K processor has 5GT/s which corresponds to 2.5GHz.
This means that in order to avoid a bottleneck with the RAM, it should have a speed of 2.5GHz? -
The i7-3770K processor has 5GT/s which corresponds to 2.5GHz.
This means that in order not to have a bottleneck with the RAM, these should have a speed of 2.5GHz?Let's see the DMI now connects the CPU with the chipset and does the old FSB task, but as I said the RAM goes directly to the CPU so it doesn't use the DMI (which is what has 5GT/s of bandwidth). There is still a BLCK (that's what goes to 100MHz that you mentioned), a base clock that marks certain speeds, when before it was the FSB speed but in Sandy/Ivy it's irrelevant because it's blocked I think with Haswell that changes.
So the issue is that the CPU assigns certain bandwidths (DMI, RAM, main PCIE) that give the maximum performance, which are not usually reached, in the case of the RAM for your CPU: ARK | Intel
Core™ i7-3770K Processor (8M Cache, up to 3.90 GHz) you will see that it is 25.6GB/s but if I'm not mistaken that is divided between the two channels with what would correspond to DDR3 1600.In practice if you look for tests you will see that the boards support with OC memory of higher speed and work well in synthetic tests they give better speed but in applications it is hardly noticeable. And I don't know how OC affects the CPU for memory higher than 1600, I think they recommended raising some voltage, but what seems clear is that it doesn't pay off too much.
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Well, I understand it now.
The maximum transfer rate of the RAM is 25.6 GB/s. Between the 2 channels 12.8GB/s.
DDR3-1600 has a maximum transfer rate of 12,800 MB/s, so putting 2 modules of xGB DDR3-1600 is the perfect combination with that processor.With the graphics card, you also have to take into account specifications such as the base frequency of the graphics or the maximum dynamic frequency of the graphics? Or does the graphics card go free?
I don't have that processor, but I like to know these things to know what I buy.
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The maximum transfer rate of the RAM is 25.6 GB/s. Between the 2 channels 12.8GB/s.
DDR3-1600 has a maximum transfer rate of 12,800 MB/s, so putting 2 modules of xGB DDR3-1600 is the perfect combination with that processor.That's the theory but I already say that with OC you can put faster memory, the question would be for what?
@cslbcn:With the graphics card you also have to take into account specifications like the base frequency of the graphics or the maximum dynamic frequency of the graphics? Or does the graphics card go free?
There is a link for the main PCIE of (for that CPU in 1155) PCIE 3.0 with 16X bandwidth and will be distributed between 2 or 3 long slots. And through the DMI the secondary one with less bandwidth, there are also boards with added controller to use that bandwidth for more graphics. A single GPU does not reach to use the full bandwidth of a PCIE 3.0, nor two, from there you could be interested in something else.
@cslbcn:I don't have that processor, but I like to know these things to know what I buy.
¬¬ well you're already giving me positive votes.
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There's a link for the main PCIE (for that CPU on 1155) PCIE 3.0 with 16X bandwidth and it will be shared between 2 or 3 long slots. And through the DMI the secondary one with lower bandwidth, there are also boards with added controller to use that bandwidth for more graphics. A single GPU doesn't use the full bandwidth of a PCIE 3.0, nor do two, after that you might be interested in something else.
So… no matter how good a single graphics card is, it will never reach the theoretical maximum of the pci-e 3.0 bandwidth?
In the processor description, it says Maximum dynamic frequency of graphics = 1.15GHz. What does that refer to?
¬¬ well you're already giving me positive votes.
XD I've already given them. I don't have it yet, but soon I will buy a new computer and now I already know which parts I should buy
Look at the bright side, with this post I avoid the typical post of… which processor do you recommend... which ram do you recommend... -
So... no matter how good a single graphics card is, it will never reach the theoretical maximum of pci-e 3.0 bandwidth?
In the processor description, it says Maximum dynamic graphics frequency = 1.15GHz. What does that mean?
XD I've already given them to you. I don't have it yet, but I'll buy a new computer soon and now I know what parts I need to buy
Look at the bright side, with this post I avoid the typical post of... what processor do you recommend... what ram do you recommend...I like it
No idea, use Google to see what it says. Not any current graphics card, no matter how good.P.D. Anyway, remember that the 3770 is already the old generation... And to buy, you have interesting guides on the forum, it's not very complicated to choose the basic components and then if you want to share your shopping list so that we can advise you, we will be delighted
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For gaming 2x4GB is fine and 2133 doesn't skyrocket in price, for 80€ you have some nice memories at home, something like this:
G.Skill Ripjaws X DDR3 2133 PC3-17000 8GB 2x4GB CL9 F3-2133C9D-8GXL DDR3 Memory
Leaving 100€ is silly.
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The fact is that if you look for comparisons you will see that in a game there is no difference in using ram at 1600 than at 2100, because the game uses the memory of the graphics. And it is also not noticeable in many other tasks, so I prefer to spend on putting more quantity than more speed to which it is complicated to get performance.
AnandTech | Sandy Bridge Memory Scaling: Choosing the Best DDR3
PD. But it is curious that there is not much difference in price for speed right now (it should not be sold), and I do not remember that 16gb were so expensive the last time I bought… I just looked and they came out at 90 and there were even cheaper ones.
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PD. De todas formas recuerda que el 3770 es ya es la antigua generación…
La nueva generación es la tercera no? el i7-3770 no es de la tercera?
Para jugar 2x4GB ya va bien y 2133 no se disparan de precio, por 80€ tienes unas memorias majas puestas en casa, algo tal que esto:
Para jugar 2x4GB ya va bien y 2133 no se disparan de precio, por 80€ tienes unas memorias majas puestas en casa, algo tal que esto:
G.Skill Ripjaws X DDR3 2133 PC3-17000 8GB 2x4GB CL9 F3-2133C9D-8GXL Memoria DDR3
Dejarse 100€ es tontería.
Pero DDR3 2133 tiene una capacidad máxima de transferencia de 17GB/s. Si se ponen 2 modulos en dual channel, serán 34GB/s. Esas memorias para un procesador i7-3770k son demasiado potentes y no merece la pena gastarse tanto dinero.
Si no me equivoco, el mejor procesador para socket 1155 es el i7-3770. Para este procesador la memoria ddr3 1600 va perfecta.
Para los socket 2011, los procesadores tienen una tasa bastante alta, a partir de los 50GB/s. Con estos procesadores se han de usar DDR3-2200 y aún con esto no basta. Imagino que habrá que poner 4 modulos, no?
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The current one is haswell, it would be the 4770 socket 1150. The 2011 uses quad channel not dual, and gives twice the width.
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Don't worry about bandwidth, I'll tell you the comparisons I've seen, real test environment. Those 2133 cost you about 1866. In pcc you also have 1600 with high latencies 7€ cheaper or my 1333 16€ cheaper. If you go for price you buy the Crucial and put them at 1600, if you go for performance get those G.Skill.
Editing: As for the i7, I insist, forget about buses and various theories, don't get too carried away with the memories that are a few euros. What you need to clarify is if you rent the virtual threads because you would pay for them more than 80€. To play in general I already told you no (rare is that a game benefits from HT), better put them in the piggy bank or spend it already on GPU, with a 3570K it's already good. For calculations, design/editing and compression/decompression you'll get a slice of the 8 threads and even for this, if it's casual, an i5 is enough.
