P55 Chipset - Quick Primer
by Gary Key on September 8, 2009 12:15 AM EST- Posted in
- Gary's First Looks
It Slices, It Dices. But Wait, There’s More!
Actually, there is not more. A couple of years ago rumors were floating around that Intel’s first Platform Controller Hub (PCH) would contain the latest in features like 6Gb/s SATA ports, USB 3.0, and full PCI Express 2.0 capabilities all at a price that even McDonald’s would be envious of when launched. Of course, you know rumors are usually just that, silly rumors.
Instead, we end up with what I would conveniently call ICH10.1. Even Windows 7 agrees with us when loading drivers. Except that PCH is the new ICH, otherwise we are talking the same part, almost. There are a few minor differences between the P55 and ICH10R as we see below.
| AMD SB750 | Intel ICH10R | Intel P55 | |
| Additional PCI Express | None | 6 x1 PCIe 1.1 | 8 x 1 PCIe 2.0 |
| USB | 12 ports | 12 ports | 14 ports |
| SATA (300MB/s) | 6 ports | 6 ports | 6 ports |
| PATA | 2 channels | None | None |
| RAID* | RAID 0/1/5/10 | RAID 0/1/5/10 | RAID 0/1/5/10 |
| HD Audio Interface | Yes | Yes | Yes |
| Ethernet | Not Integrated | Intel Gigabit LAN | Intel Gigabit LAN |
| Northbridge Interface | 4 lane PCIe 1.1 | DMI 10Gb/s each direction, full duplex | DMI 10Gb/s each direction, full duplex |
The P55 gives you six 3 Gb/s SATA ports, 14 USB 2.0 ports, a Gigabit Ethernet MAC , HD Audio, and eight lanes of PCI Express 2.0 goodness all for $40. That price tag buys you two additional USB ports and two additional PCIe lanes over the $3 ICH10R. The PCI Express lanes are version 2.0 but Intel decided to limit their speed to PCIe 1.x specs at 2.5GT/s. Why? We think it is because the DMI link continues at 1GB/s in each direction, which means a decent 6Gb/s SAS/SATA RAID card and a few upcoming 6Gb/s drives (SSDs anyone) could easily saturate the link. The P55 and ICH10R both consume a little over 4.5W during normal operation. Considering the specifications on AMD’s new SB8xxx chipsets, it appears we have a PCH Gap brewing.
How is performance? We are still trying to reach a conclusion and asked Intel for additional information. Overall, the two chipsets are about even in actual usage that includes file transfers and application benchmarks. The synthetic programs like HDTach and HDTune tell another story but one that we do not trust. Iometer shows both controllers neck and neck with our WD VelociRaptors in RAID testing, but a slight nod to the ICH10R in single disk testing with our OCZ Vertex 120GB SSD. We will have results in the upcoming P55 motherboard roundups (three total) starting later this week.
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Zap - Tuesday, September 8, 2009 - link
That's exactly the first thing I thought of when I read this page.I guess Intel has to protect their chipset business revenues now that they don't have an extra Northbridge to sell.
milleron - Tuesday, September 8, 2009 - link
I'd have to answer with a question. Do the Lynnfield CPUs -- i5 750, i7 860, and i7 870 -- require the P55 i.e., are they incompatible with X58/ICH10? Can you build a socket 1156 motherboard without a P55 chipset? I have no idea, but I'll guess that someone here does.
Casper42 - Tuesday, September 8, 2009 - link
ICH10R is only a SouthBridge. You need a P45, G41, G43 or G45 Northbridge to go with it to build a complete picture.P55 is a PCH which is a combination of the North and South.
The original author did us all a dis-service by not including the price of the NB just to keep things level.
Core2/P45/ICH10R
Memory Controller: North - Dual Channel DDR2/DDR3
PCIe Lanes: x16=North (16 2.0 lanes), x1=South (6 1.0 lanes)
Core i7/X58/ICH10R
Memory Controller: CPU - Triple Channel DDR3
PCIe Lanes: x16=North (36 2.0 lanes), x1=South (6 1.0 lanes)
Core i5/P55
Memory Controller: CPU - Dual Channel DDR3
PCIe Lanes: x16=CPU (16 2.0 lanes), x1=PCH (8 2.0 crippled lanes)
Common
SATA: South
Audio: South
USB: South
Network: South
Socket 1156, which is what the Core i5 (and that stupidly named Core i7 800 series) all use currently only has 1 Chipset available:
The P55
So to answer your question, NO, you cannot (currently) get a 1156 without a P55.
It does raise a valid question though. If you look at what the ICH10R provides, its damn near identical to what the PCH does, also uses DMI as an interconnect and costs a fraction of the P55.
So it might be technically possible, but someone alot smarter than I must know why it is not being done.
faxon - Wednesday, September 9, 2009 - link
my understanding was they changed the architecture of the P55 PCH in such a way so as to make it physically impossible to interface the CPU directly to an ICH10R instead, both to protect their chipset business and to prevent manufacturers from breaking the product somehow in the redesign stage such that it looks like it was intel's fault, giving them bad press as a result. ultimately they did design the CPU and the chipset, so if they were made capable of interfacing, but it just didn't work and whoever tried to fix it F*ed up, then joe sixpack out there would blame intel for delivering them a crappy computer as a result. intel also has the H55 chipset in the pipes, which will be designed to interface with the core i3 CPU/GPU MCM by providing video outputs on the board, something P55 lacks as of now. if you think about the price segment that a board which just uses CPU + ICH10R would fall into, it will cut directly into the price segment in which H55 will fall into when it is released. in the end, you would end up with a lot of confused customers and a ton of boards which didnt fall anywhere in intel's marketing lineup either lolyacoub - Tuesday, September 8, 2009 - link
Gary - Do you have an ETA for the motherboard articles, particularly the review of the MSI uATX and ATX offerings?I'm guessing the P55 motherboard articles are all complete or nearly complete but will be released over the course of the next few days instead of all at once... just curious how long to wait before we see the MSI reviews since those interest me most.
Thanks :)
Dariak - Tuesday, September 8, 2009 - link
"... We will have results in the upcoming P55 motherboard roundups (three total) starting later this week. "
yacoub - Tuesday, September 8, 2009 - link
Thanks - either that line wasn't there earlier or i missed it.Mr Alpha - Tuesday, September 8, 2009 - link
Wait, is the DMI 1 gigbyte or 1 gigabit?Ryan Smith - Tuesday, September 8, 2009 - link
DMI is a 10Gb full duplex link. Somehow a 0 rolled away from us on that. Sorry about that guys, it's fixed.MadMan007 - Tuesday, September 8, 2009 - link
Something still doesn't add up. I can't work out how 2GB/s as in Intel's slides works out the same as '10Gb/s full duplex.'