By: Michael S (already5chosen.delete@this.yahoo.com), November 10, 2008 5:55 pm
Room: Moderated Discussions
EduardoS (no@spam.com) on 11/10/08 wrote:
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>Michael S (already5chosen@yahoo.com) on 11/10/08 wrote:
>---------------------------
>> likely compatible
>>with incoming Nehalems => simplified spare parts management.
>
>No, Nehalem is DDR-3 only, 5100 is DDR-2
Are you sure that when Nehalem server parts come out they wouldn't support registered DDR2 DIMMs?
I didn't follow all recent DDR3 developements. When it originally came out people claimed that it would be limited to 3 or 4 ranks per channel. Do things changed?
>
>>Aren't you confusing 5100MCH chipset with 3000/3100? Registered DDR2 and triple
>>PCIe x8 don't look like desktop features to me.
>
>Look at old Athlon 64 FX for registered DIMMs,
Very old A64-FX, you mean.
That happened out of necessity. U-DIMM parts with 1MB cache were not ready while gamers were super-enthusiastic about K8 and willing to pay big $$$. So AMD decided to collect the money with renamed Opterons. When 1MB S939 parts came out these early FX CPUs quickly fail out of fashion. You probably remember the whole story better than I am.
>many entusiasts motherboards today
>feature 3 or even 4 PCIe x16 (but only 4 x8 lanes), compare these to 6 PCIe x8 present on Sun X4250.
x16 is a desktop feature. x8 is most popular in servers. Would you disagree?
>
>And don't forgot about the south bridge, the same ICH-9R present on P5K-E for example.
>
What's wrong with ICH-9R? It seem to have most of the features desirable for low end server.
As to Sun X4250 it achieves 6 x8 slots with three PCIe switches. That's good for flexibility but the bandwidth to main memory can't be magically created by the switch. It seems to me that aggregate bandwidth between I/O and memory is actually lower than on 5100MCH because on the later all three x8 slots are directly connected to MCH while on x4250 like in all other 5000P-based systems the third x8 link is attached to IOH.
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>Michael S (already5chosen@yahoo.com) on 11/10/08 wrote:
>---------------------------
>> likely compatible
>>with incoming Nehalems => simplified spare parts management.
>
>No, Nehalem is DDR-3 only, 5100 is DDR-2
Are you sure that when Nehalem server parts come out they wouldn't support registered DDR2 DIMMs?
I didn't follow all recent DDR3 developements. When it originally came out people claimed that it would be limited to 3 or 4 ranks per channel. Do things changed?
>
>>Aren't you confusing 5100MCH chipset with 3000/3100? Registered DDR2 and triple
>>PCIe x8 don't look like desktop features to me.
>
>Look at old Athlon 64 FX for registered DIMMs,
Very old A64-FX, you mean.
That happened out of necessity. U-DIMM parts with 1MB cache were not ready while gamers were super-enthusiastic about K8 and willing to pay big $$$. So AMD decided to collect the money with renamed Opterons. When 1MB S939 parts came out these early FX CPUs quickly fail out of fashion. You probably remember the whole story better than I am.
>many entusiasts motherboards today
>feature 3 or even 4 PCIe x16 (but only 4 x8 lanes), compare these to 6 PCIe x8 present on Sun X4250.
x16 is a desktop feature. x8 is most popular in servers. Would you disagree?
>
>And don't forgot about the south bridge, the same ICH-9R present on P5K-E for example.
>
What's wrong with ICH-9R? It seem to have most of the features desirable for low end server.
As to Sun X4250 it achieves 6 x8 slots with three PCIe switches. That's good for flexibility but the bandwidth to main memory can't be magically created by the switch. It seems to me that aggregate bandwidth between I/O and memory is actually lower than on 5100MCH because on the later all three x8 slots are directly connected to MCH while on x4250 like in all other 5000P-based systems the third x8 link is attached to IOH.