Socket 754 or 939?

[watdahel]

I need to build a PC based on AMD. Which cpu socket is the way to go, 754 or 939? Is it better to have a 1 MB L2 cache than 512 KB even if the latter has higher clock speed? For the CPUs that run at 1 GHz fsb, will I be overclocking the memory as well. DDR400 goes upto 400 MHz after all.

 

[mordantmonkey]

754 is pretty much a dead socket. if you are trying to save money however, it isn't a bad option, and they will continue making semprons (AMD's budget chip) for 754 for a while. but for performance(dual channel memory) and better motherboard options you probably want to go with 939. However, they are not creating new chip lines for the 939 anymore, as AMD is moving to the AM2 socket. Cache is not nearly as important for AMD as it would be on an Intel chip. Price being equal i'd go for the higher clock speed.
unless you mess with the bios, the memory will not be overclocked.

 

[nitromullet]

I think a big reason to go with socket 939 is that there are more PCI-E x16 motherboards available for socket 939. Head over to the video forum if you want to see all the people willing to pay too much for an AGP card just to keep their Northwood and socket 754 systems alive. Socket 939 should be a around for a while as well.

...there is still good news for those on DDR1; Socket 939 will stick around well into Q1'07 on the performance desktop - and well beyond that for Sempron. In fact, AMD's latest roadmap goes all the way to Q2'07 with Socket 939 Sempron.

http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=2587

You also indicated that you are going to be overclocking as well, check out the socket 939 Opterons...

Edit: another advantage: with socket 939 you can go dual core as well.

 

[Zap]

How I see it:
clock speed > dual channel (socket 939) > cache size

There isn't much of a choice between the two sockets. It really comes down to your budget. If you can seriously only afford $150 for a CPU/mobo combo, then it doesn't matter how much better socket 939 is because you can't afford it. Socket 754 has CPU/mobo combos from Fry's for as low as $70. Your choice of boards and CPUs from vendors such as Newegg starting at $100 for the combo (cheapest board/cheapest CPU).

At the same clock speed and cache level socket 939 is better, but cost of entry is higher. Lowest socket 939 combo at Fry's is $170 IIRC, and from reputable online vendors you may not be able to get anything for under $200.

Basically if you can afford socket 939, may as well get it. If not, don't sweat it and be happy with socket 754.

 

[rmed64]

exactly what above poster said. Yea, dual channel is nice, but its not gonna make your system much faster than an equally clocked 754 cpu. Sempron 64 overclocks are huge, and they are inexpensive processors. When you are benching a Sempron 64 2800+ at Athlon 64 3500+ speeds, it makes you feel soo warm inside.

 

[watdahel]

What's the difference between sempron and the athlon 64? I've seen them both 90nm with same cache sizes but sempron being cheaper.

 

[F1shF4t]

Originally posted by: erwin1978
What's the difference between sempron and the athlon 64? I've seen them both 90nm with same cache sizes but sempron being cheaper.

Sempron have either 128k or 256k cache sizes
Athlon 64 have either 512k or 1024k cache sizes

 

[CKXP]

s754 semprons have 128kb/256kb cache depending on the model, a64's have 512kb/1mb cache. right now newegg has a pretty good deal on a 3000 venice s754 link. s754 is still a nice option if you're on budget and there are NF4 s754 motherboards available even in SLI

 

[watdahel]

So what's the consensus on which motherboard to get and most importantly which chipset? nforce or via or sis or whatever else?

 

[imported_Sincity]

Erwin,

Read the Sticky on Mobos. A good budget board that OCs well is the Epox. If you live near a FRY's you can get a sweet deal on one of their bundles. Usually they pair it with a budget ECS board. However, I got on a deal at FRY's where the Abit AN8 SLI was $100 after rebate and tax. Pair that up with a Venice 3000+ E3 stepping and you will be hitting 2.6 ghz territory. Some stores still carry those early E3 3000+. Newegg no longer carry them. You can go online and look around. I just sold a 3000+ Winchester for $126 shipped this week.

My dilemna was jumping on the 939 platform so late since AM2 is coming out soon.

Good luck.

 

[Zap]

The "whatever else" would be ATI and ULi chipsets. At stock speeds they all perform about the same. For overclocking, the easy choice would be Nforce, though there are some overclockable ATI chipset boards. Some SiS and ULi chipset boards can be overclocked, but most don't have much options and even the overclockable ones don't give you much voltage, if any. As Sincity said, read the sticky.

 

[watdahel]

Is it really fair to compare Semprons and Athlon 64? I would think not. Can a Sempron 3400+ spank a Athlon 64 3200+? Who will win the battle of the beats? What about Turions? I heard they beat everything and only requires half the watts.

Who should I consider for my rams? Do I need to install DDRs in pairs?

 

[Flipped Gazelle]

Originally posted by: erwin1978
Is it really fair to compare Semprons and Athlon 64? I would think not. Can a Sempron 3400+ spank a Athlon 64 3200+? Who will win the battle of the beats? What about Turions? I heard they beat everything and only requires half the watts.

Who should I consider for my rams? Do I need to install DDRs in pairs?

Yes, it is eminently fair to compare Semprons and Athlon 64s if they are similarly priced. On the S754 platform they are actually in direct competition with each other. I'd imagine a Sempron 3400 would perform similarly to an Athlon64 3200 in most cases. Turion is really the Athlon 64 Mobile piece, and at full power uses more than half the wattage of it's desktop sibling.

DDR need not be installed in pairs.

 

[Zap]

Turion would perform exactly the same as any other socket 754 CPU of the same MHz and cache. Power consumption may be a bit less from lower voltage, MHz being equal.

You need to install DDR in matched pairs if you go with socket 939. Socket 754 is best off with a single stick. Other configurations work, but those are ideal.

It certainly is fair to compare Semprons and Athlon 64... at the same price points. The socket 939 3200+ is $160. The Sempron 3400+ is $123. If you can't shell out the extra $37 (plus extra $$$ for motherboard) then by all means the choice is clear - get the Sempron. At this time there is absolutely no cheaper socket 939 CPU at Newegg (just a random choice for an example). If you are looking at the A64 3000+ Venice for socket 754 and the Sempron 3400+, then the A64 is the better deal for only $3 more at $126 (same socket and MHz, twice cache). Let's compare A64 3000+ Venice for socket 754 versus Sempron 2600+. If you absolutely can't afford the $61 more for the A64, get the Sempron.

Translation (if that is too obtuse): Chose your price point. At that price point, get the faster true MHz CPU. If two CPUs are same MHz, get the one with more cache and/or dual channel. Something like that...

 

[watdahel]

Good stuff.

DDR400 support for mobos is pretty much standard I see. I also see there's DDR500 rams available. If I get those would I have to overclock the fsb in order to take full advantage of DDR500?

Also, is it wise to get the DDR500 as opposed to DDR400 even if the latter has faster ratings?

 

[BUrassler]

Originally posted by: erwin1978
Good stuff.

DDR400 support for mobos is pretty much standard I see. I also see there's DDR500 rams available. If I get those would I have to overclock the fsb in order to take full advantage of DDR500?

Also, is it wise to get the DDR500 as opposed to DDR400 even if the latter has faster ratings?

I would also Like to hear the answer to this please!?

 

[Zap]

On overclocking the FSB, yes and no. Some boards with newest BIOS revisions and newest CPU cores will give you higher RAM options. Benefits are probably minimal.

Most DDR500 can run slower speeds at lower latencies (though I had a few Kingston HyperX PC4000 that wouldn't run CAS 2 at any speed). Most low latency DDR400 can run higher speeds at relaxed latencies. Neither is 100% guaranteed though, so you may want to decide on your overclocking philosophy before purchasing.

My personal preference is to get low latency DDR400.

 

[Zap]

Oh yeah, forgot to add...

My reason for lower latency (besides personal overclocking philosophy) is that the integrated memory controller makes the most out of the existing bandwidth. Intel's Netburst architecture for their P4 CPUs is known to like more memory bandwidth but generally speaking the A64 architecture is not bandwidth starved.

 

[watdahel]

The socket 939 boards support 1GHz hypertransport while the 754 support only 800 MHz hypertransport. Is that the fsb? So getting a DDR500 with socket 939 is best since you don't overclock the fsb?