View Full Version : differences of 939 and 754
wht is the differences between these two sockets? most of the 754 CPU had a 512k L2 cache, the 939 had 1m L2 cache.
besides this wht is the differences? more power saving? lower temperature? better hypertransport? upgrade for future 939 CPU? or others?
01-23-2005, 08:18 AM
Well the doubling of the L2 cache could be nothing but good I suppose - But from the other thing you said, yes the 939 does provide more upgradability, in that the 754 pin;s are no longer being made, 939 is their current choice, and it seems they will stick with it for a while, but that's purely a guess from me.
01-23-2005, 08:35 AM
The main difference is that 754 socket is a Single Channel Ram CPU whilest the 939 counterpart is Dual Channel. If you do go for the 754 make sure you get 1 meg cache because it really makes a big difference otherwise I would go for 939. (well price sometimes differs as well)
01-23-2005, 08:46 AM
In addition to a new core, the 939 was introduced to pave the way for pci express. This is a watered down version of the opteron, simply put.
the 754 is still in production, it's just an athlon forced into 64 bit.
it's just an athlon forced into 64 bit.
Well.. not really. The socket 754 chips are exactly what you find in the opteron, except you do not get dual channel, (thus you lose quite a few pins) you dont need registered memory (loss of one pin) and the cache size is smaller (512k)
On the socket 939, you get dual channel memory, and the peace of mind of knowing this socket has a future (Dual cores) :P Otherwise, its the same thing as the 754 chip (core differences excluded). Only the FX and the Athlon64 4000+ have 1MB cache. And maybe some earlier revisions of the Athlon64 on the 754 socket. On the Opteron (socket 940) you get the registered ECC memory requirement and a 1MB cache. Those are really the main differences.
All 3 chips have onboard memory controllers and share the same basic design. So saying that the socket 754 chips are Athlons (I assume you mean XP?) forced into 64bit, is a bit of a false statement.. Especially considering Windows does not yet have a 64bit (commercially available) OS for the Athlon64/Opteron, hence they run in 32bit mode.
Also on the Athlon64/Opteron architecture, cache sizes seem to matter very little (at least at very small incriments) due in part to the speed of the onboard memory controller. Not saying that bigger cache size is bad, just saying that the difference is not as great as you would think.
"The main difference is that 754 socket is a Single Channel Ram CPU whilest the 939 counterpart is Dual Channel. If you do go for the 754 make sure you get 1 meg cache because it really makes a big difference otherwise I would go for 939. (well price sometimes differs as well)"
so, can i say the 939 is actually a kind of dual core? and there is a difference in quality between 939 and 754 with same L2 cache? the 754 not supporting dual channel ram? and 939 is no better than 754? the 754 also got 1m cache, 3200+, isnt it?
hey check it out, Asrock ULI M1689, more is coming...
01-23-2005, 07:51 PM
939 isn't Dual core it just has double the bandwidth to memory. ie 754 has 3000MB/s and 939 has 6000MB/s.
Some 754 have 1 meg caches some don't, the earlier 754 have 1 MB cache and the latter 754 only have 512 just like the 939 ones.
Quality wise their isn't anything you can gripe about. I guess it depends on your budget. The CPUS are identical inside except for that memory controler issue and some cache differences.
One advantage that 939 has over 754 is that it has longer Roadmap while the 754 is pretty at its end of life.
01-26-2005, 03:15 PM
939 have dual DDR compatibility 754 donT
939 have PCI express compatibility 754 donT
939 have future 754 donT :)
754 socket will be used for semprons and all a64 family will be going for socket939
01-26-2006, 04:00 PM
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