Question about FSB / Memory frequency...
Question about FSB / Memory frequency...
Adjusting your FSB frequency boosts the entire setup, including the memory. Therefore, increasing the FSB speed not only speeds up the CPU but also affects the RAM and other components. This is why CPUs with unlocked multipliers are preferable; you can adjust the multiplier directly rather than changing the FSB, which only impacts the CPU.
If you've overclocked using your FSB, you might need to lower the RAM speed to ensure proper operation. This is one of the limitations of FSB overclocking—sometimes you're constrained by the system's most restrictive part, not just the CPU.
Based on what I read, it would be wise to review some fundamental overclocking guides before attempting any changes. Pushing your FSB to its limit in a single attempt can be risky. You might end up with a system that’s too limited for the rest of the components.
Overclocking requires patience and careful handling, especially if you're new to it. It's important to make small adjustments, test each change, and observe the results. The process can be lengthy and sometimes not worth the effort or stress.
Using my own setup as an example: I have a X2 240 2.8 CPU on a BIOS board with 4 GB of RAM. It’s not particularly expensive—around $70 for the CPU, $60 for the motherboard, and possibly another $100 for matching RAM. If you plan to overclock, you’ll need an aftermarket heat sink, extra fans, or a better case for cooling. Upgrading the RAM to a higher rating could also be beneficial.
If I were to push it further, I’ve seen people claim 3.7 from a 240 MHz CPU, but I only managed 3.5. This made me reconsider copying their settings or doing calculations to determine the right FSB speed for better performance. After all, his setup could be flawless.
Things can go wrong, and you might end up damaging your $70 CPU and RAM if things don’t work out. Replacing them would cost around $150, depending on whether my motherboard still functions.
On the other hand, if I wanted a system with 3.0 or higher, the Phenom X4 965—a quad-core model with 3.4 GB RAM and an unlocked multiplier—would be a better choice. It’s available for under $200 and would outperform my overclocked 240 right away, without any hassle.
And the biggest drawback? When I pushed my system to 3.5, it benchmarked well but didn’t show a noticeable improvement in real-world performance for my typical usage. Risking damage to my computer just to get a marginal gain isn’t worth it. Smart, right?
Think about this.
And you know what they’re thinking:
"Shut up dad!"
LOL
The A64 chips lack a FSB, which was the main idea behind my discussion. Or maybe they actually have two FSBs. They rely on an HT bus for all communication with the memory, and a separate dedicated controller just for the memory (or at least I think that’s the case). But regardless, my question remains – how can you avoid slowing down your system if you don’t run your FSB/memory controller at the same speed as your RAM? In my setup, this means I’d have to set my CPU bus frequency to 800MHz, which is what the BIOS calls the on-chip memory controller. How would the CPU keep up with my DDR3 1600 RAM?
And assuming the 'Core Bus Freq' influences beyond the memory bus, can anyone clarify what it actually does? I thought it only affects the HT and as a direct outcome the NB. But if it has broader effects, why do people recommend keeping the FSB at 200hz and increasing the CPU core multiplier instead? Wouldn't raising the FSB to something like 400hz improve memory performance, then lower the HT/NB clock if they can't handle that high FSB?
my ram runs at 800mhz and the fsb is at 200, giving a 4:1 ratio. increasing the fsb would require lowering the multiplier, which affects ram speed and might need higher voltage and new timings. changing the multiplier keeps the ratio constant but changes ram speed. if you lower the ram speed to 667mhz with a 3:10 ratio, it would need to run at 833mhz, requiring significant overclocking. in this scenario, the two components must sync so their ratios align at a common point. in the second case, a 3:10 ratio means both numbers meet at 2500mhz. because my 955 works at 3.2ghz with a 200x16 setup, it seems possible to adjust for higher speeds, though it depends on whether the cpu can handle it.
I'm really unsure how to describe this, so you'll grasp it better. You're probably puzzled about the process. Don't worry about changing anything. If your FSB/core bus speed is 200 and you have 800 RAM, it's already running at 800. Use cpuz and verify it. It will automatically adjust when you install the RAM and start the machine. Also, cpuz will operate at half speed, so don't let that mix things up. 800 RAM should read as 400; you need to double it for the right frequency.
On some motherboards, you can tweak memory settings separately, like adjusting the multiplier or clock speeds for overclocking or underclocking. But if it's set to auto, you don't need to make any changes. With FSB set to stock, the memory controller is already configured correctly for your RAM.
The only situation requiring adjustments is when you're trying to overclock the CPU using the FSB/core bus frequency and increasing it. This can affect the whole system, including the RAM. If you push it too high, you might need to underclock the RAM to maintain stability. Like lowering the multiplier or resetting the RAM to its original setting. Without checking my BIOS, I'm not sure of the exact numbers.
But yes, you could overclock your memory this way. You can increase the FSB frequency and reduce the multiplier for your CPU. This would boost the rest of the system while keeping your CPU speed lower. Why would you do this? I have no idea, since you probably won't see any performance improvement. CPU speed usually gives better gains than memory overclocking. At least based on my experience, slower RAM speeds generally don't significantly affect performance. I haven't experimented with my RAM yet.
I'd prefer to overclock the CPU and underclock everything else if necessary. I haven't noticed RAM speed having a major impact on performance. It's not something I worry about much.
The numbers you mentioned are quite high. Doubling your FSB from 200 to 400 is extreme, especially if your system doesn't allow it. Raising it to 230 or 240 could push 800 RAM to 1000, but at 400 it might not even boot. And I'm not sure the CPU multiplier affects RAM speed much, do you think? My CPU's multiplier is fixed at 14x, but I can adjust it. Lowering it would likely reduce RAM speed too, as confirmed by cpuz. I haven't tried changing it yet, so I can't be certain. Maybe I'll look into it later.
Paul
from what ive come to understand on AMD systems you cant really touch the Reference frequncy. Youre stuck at 200mhz becuase the whole system including the NB runs at that. If you touch it a bit the system will probably go wonkie. There is probably a TINY bit of room to up the frequency, but not much.. maybe 210-215, and youd be at the upper edge of stability. Everything gets over clocked when you do this - the entire system, so expect more heat, less stability, etc. And from what I understand there is no benefit to running a 1:1 like the op suggests/talks about.. The ratio is the same 1:4, etc, it all scales and = the same thing.
I just saw you have a Black Edition CPU, if I were you I wouldn't even adjust the frequency setting, just increase the multiplier since it's unlocked for you.
I've had my frequency set to 250, you just need to tweak other settings back.
Paul
I have a question about this setup. If I adjust the FSB to 400 and modify the NB multiplyer from 10 to 5 while keeping the same output, and change the RAM speed from 400 to 200, the HT multiplyer from x4 to 2x, then lower the processor multiplyer from 14 to 7, would doubling the FSB and halving all multipliers bring it back to normal? I believe this is how it works, but I’m not sure if the FSB actually just acts as a multiplier.
Your RAM is the most efficient component, you're not causing any bottlenecks by not maintaining a 1:1 ratio. I adjust my ratio from 1:2 to 1:4 and it doesn't seem noticeable. Don't worry about your ratio, just confirm your timings, voltage, and frequency are accurate.