E5645 or L5640?

E5645 or L5640

  • Total voters
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nitrobass24

[H]ard|DCer of the Month - December 2009
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ok so im upgrading.

I can get the following CPUs for my SR-2 and im not sure which to go with.

2x L5640s - $700 total
2x E5645s - $1000 total

Which one and why?
 
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is that price for each or both? Cuz if its each the 5640 are on ebay for 350...
 
not much difference besides the fact that the 5640 is multiplier lower then the 5645.. so id go with the 5640..
 
For the highest overclock the 5645 would be the smarter choice. My L5640 is maxing out at 3.6Ghz but I can push it to 3.77Ghz.I also have a E5645 being delivered on Tuesday so we will see how much higher I can go.
 
DBZ33 said:
For the highest overclock the 5645 would be the smarter choice. My L5640 is maxing out at 3.6Ghz but I can push it to 3.77Ghz.I also have a E5645 being delivered on Tuesday so we will see how much higher I can go.
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being that its only x1 multiplier higher you will probably get 3.87ghz.. but is it really worth 300 more dollars for 100 mhz? that tis the question.. but i guess we'll find out on tuesday.. :p
 
sirmonkey1985 said:
being that its only x1 multiplier higher you will probably get 3.87ghz.. but is it really worth 300 more dollars for 100 mhz? that tis the question.. but i guess we'll find out on tuesday.. :p
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Would it be a guarantee the E5645 will OC close to 4GHz or higher in a good motherboard? I think that should determine whether the additional $300 is worth it or not. The cost difference is significant IMO. One can buy RAM with what is saved for example. Can't really vote unless I know what the max OC for the E-series might be.
 
APOLLO said:
Would it be a guarantee the E5645 will OC close to 4GHz or higher in a good motherboard? I think that should determine whether the additional $300 is worth it or not. The cost difference is significant IMO. One can buy RAM with what is saved for example. Can't really vote unless I know what the max OC for the E-series might be.
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well the problem really comes down to the limitation of the SR-2 motherboard.. the board eats shit at 200 blck or higher.. so to break 4ghz it all depends on the multiplier of the processor..

so say if his board as well suffers for the 200blck limit then the most he will get is 200x18 or 3.6ghz.. or if you can use the turbo multiplier 200x19 = 3.8ghz(going by the es model being sold on ebay since i cant find official numbers on the turbo multiplier).. if ya want to go balls out and try to hit the bleeding edge you might hit 4ghz.. but for 300 extra dollars i dont even think its worth bothering with but hey its not my money..
 
Are you sure the E5645 has turbo? That would be a big factor. We don't have any of these chips running right now, so we don't know how well they overclock.

If you are happy with 3.6 GHz and 110K ppd on good work units, go with the L5640. That is pretty well known. Personally, I would go with the E5645 if you can confirm it has the 19x multiplier with turbo. I realize the extra 50% in initial cost seems like a lot for 1x on the multiplier, but this is the range where the multiplier is going to hold you back. If the difference was going from a 20x to a 21x multipier for example, I would say that it is not worth the extra money. Anything under 20x is worth it. You are probably looking at an extra 10K ppd with the 1x greater multiplier, which is significant.
 
Where are you finding E5645s by the way? I have yet to see one on ebay, but I may be blind...
 
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And I don't think the boards are limited at 200 bclk...I'm runing mine at 205 now, had 208 stable as the highest, If I tweaked it a bit I bet I could get 210 easy which would put me over 4.0Ghz

Ive also read plenty on EVGA about them going over 200, it's just around 190-200 that you can't leave things on auto anymore, youve got to go big or go home from there on out
 
musky said:
.. If the difference was going from a 20x to a 21x multipier for example, I would say that it is not worth the extra money. Anything under 20x is worth it. ...
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Hmmm, I am considering between the x5650 and x5660, which is exactly the scenario you describe, 20x vs 21x.

With my current SR2/5650 I feel I am CPU limited at 4.2Ghz, but with the board not too far behind. Frankly I think it is a very good match, with not much performance left on the table.

The question is if I get a second SR2, how much is it reasonable to expect to improve on the 4.2Ghz I have now. (yes, what a greedy trucker!) One school of thought is that the x5650 is really only a lower binned x5660, which is promising. Against that is that the performance scaling is going to be less than linear, so that I should not expect that 1 more multi would result in 200mhz more as we get to the ragged edge. Or I could luck out and get to 4.5+Ghz.

Normally there would be little downside other than wasting cash, but if a 5660 could only do 4.2Ghz, but in this case with the turbo bug, I would not be able to drop the multi and pretend I simply have an overpriced x5650. I would be stuck with memory performing 5% worse than if I had gone with the cheaper CPU. So I could end up with both higher priced and under performing to what I have now. Which would suck.

Do I roll the dice? :confused:
 
In both of y'alls cases I'd save the money and go with the cheaper CPU's. That money is a big diff in both cases. Also, for MIBW, I doubt you'd be able to get a folding stable 4.5Ghz OC, I've never seen a folder that high, but I guess there is always a first for these things.

If I had the funds for either, id still go with the cheaper chips in both of yalls cases. Nitro, another thing to consider is power draw
 
I am going under two assumptions:

1. An SR-2 can get 200 bclk fairly easily, and beyond that is hit and miss
2. Westmere chips are going to top out in the 4.2-4.3 range on air, regardless of which model you have

So, a 21x multipier on an SR-2 will get you as fast as you ever will get. The big money on these Xeons comes from higher multipiers since you have historically been stuck with the default 133 bclk. Now that we have the SR-2, that is no longer an issue. It is the same thing with the quad I7s - the 920/930 will run pretty much as fast as its higher-end cousins with any decent X58 motherboard, so why spend the extra money? If Intel released an I7 quad that only had a 17x or 18x multiplier, we would have a similar situation. Since the low end chips have a 21x or 22x, we don't have the problem. The same thing is true for the I7 hex cores. The low-end 970 has a 24x multiplier. I have mine at 21x, which is yielding me 4.3 GHz. That is about all the chip has in it, so I basically paid for 3x of multiplier that I don't need.

Granted, life is easier overclocking a high multiplier chip because you don't need to run at or near 200 bclk for a good result. A 26x multiplier would mean that you would only need 166 or so bclk to max out the chip. It is going to be much easier to get the board and the memory running at that speed. But, you have also paid a premium for a 26x multiplier chip.

So it all boils down to time versus money for anything over 21x multiplier. Up to that point, higher multipliers are always going to be better because they will equate to higher overclocks.

All of this is my opinion based on my experiences with Gainstown and Westmeres. You are of course free to disagree with me.
 
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Tobit said:
They go pretty quick when they are listed. Here are the last two completed auctions:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120622223744
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=220670565136
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The first one is the E5645 I won. I will post my finding Tuesday night. As far as I have been told it has a turbo 19x multiplier. The Asus P6T I have has gone to at least to 215 BCLK last time I tried but im sure its all up to the CPU. We will have to wait and see.
 
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Vaulter98c said:
And I don't think the boards are limited at 200 bclk...I'm runing mine at 205 now, had 208 stable as the highest, If I tweaked it a bit I bet I could get 210 easy which would put me over 4.0Ghz

Ive also read plenty on EVGA about them going over 200, it's just around 190-200 that you can't leave things on auto anymore, youve got to go big or go home from there on out
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Exactly. I learned this the hard way with my UD3R's and the stupid auto settings screwing up the uncore and putting it way too high.
 
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zero2dash said:
I have yet to see an x58 not hit higher than 200 so pardon my doubt here but I seriously doubt there's some limitation in place of the SR-2 that the board is incapable of 200+ bclk. Granted mine has not arrived yet but 200bclk+ is a product of many things and IME I've seen most people miss simple settings such as uncore and voltage and those are 2 big players whether or not you can hit 200+ bclk and stay stable.

Granted my board doesn't arrive til tomorrow but I'm shooting for 200+ on it and I'll be the judge for myself whether or not the board "eats shit" at 200bclk+. ;)
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I have seen too many people including myself fail to get an SR-2 at much over 200 bclk to say it is some simple setting like Uncore (which the A47 bios doesn't even have) that stops progress. I was in the same mindset as you are when I first got mine - 18x max multiplier is no big deal, I'll just crank the bclk up to 215 and call it a day. Many hours later, I am at 198 bclk. Hopefully you figure out the magic combination, but let's just say that I am not holding my breath. If you recall, I had the record of 208 bclk stable on an SR-2 for a while, but that ended when I changed over to L5640 processors. I have been stable at 202, but that is about it (and the system is faster at 198 than it is at 202.)

My point is that you shouldn't count on getting 210+ bclk when deciding what processors to get. If someone can prove me wrong, great! I'll gladly take another 200 MHz or so. I just feel that there are too many "other" factors with this board for it to be anywhere near as easy to get 210+ bclk as it is with a normal X58 board.
 
I definitely can't wait to get mine to tinker with it and see what I can do. ;)

Ooh just noticed something.
(pic copied from EVGA SR-2 forum)
wsxmp.jpg

uncore there and labeled as "QPI frequency" in the SR-2 bios. :D Yay!
 
zero2dash said:
I definitely can't wait to get mine to tinker with it and see what I can do. ;)

Ooh just noticed something.
(pic copied from EVGA SR-2 forum)
wsxmp.jpg

uncore there and labeled as "QPI frequency" in the SR-2 bios. :D Yay!
Click to expand...

Good luck with your build.But I think its more than just a QPI setting.
 
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